Microbiologically sound and stable solutions of gamma-hydroxybutyrate salt for the treatment of narcolepsy

ABSTRACT

Disclosed are formulations of gamma-hydroxybutyrate in an aqueous medium that are resistant to microbial growth. Also disclosed are formulations of gamma-hydroxybutyrate that are also resistant to the conversion into GBL. Disclosed are methods to treat sleep disorders, including narcolepsy, with these stable formulations of GHB. The present invention also provides methods to treat alcohol and opiate withdrawal, reduced levels of growth hormone, increased intracranial pressure, and physical pain in a patient.

RELATED APPLICATIONS

[0001] This application claims priority from Provisional Application No.60/113,745 filed Dec. 23, 1998, which is incorporated by referenceherein.

BACKGROUND OF THE INVENTION

[0002] I. Field of the Invention

[0003] The present invention relates generally to the fields ofpharmaceutical compositions to be used in treatments, such as, sleepingdisorders, such as, e.g., narcolepsy (particularly cataplexy), drugabuse, alcohol and opiate withdrawal, a reduced level of growth hormone,anxiety, analgesia, effects in certain neurological disorders such asParkinson's Disease, depression, certain endocrine disturbances andtissue protection following hypoxia/anoxia such as in stroke ormyocardial infarction, or for an increased level of intracranialpressure or the like. The present invention particularly relates to thefield of pharmaceutical production of microbiologically resistant andchemically stable preparations or solutions of gamma-hydroxybutyrate(GHB), also known as 4-hydroxybutyrate, and the sodium salt of GHB(sodium oxybate) and other salts such as magnesium, ammonium andcalcium, e.g.

[0004] II. Description of Related Art

[0005] GHB is an endogenous compound with hypnotic properties that isfound in many human body tissues. GHB is present, for example, in themammalian brain and other tissues. In brain the highest GHBconcentration is found in the hypothalamus and basal ganglia and GHB ispostulated to function as a neurotransmitter (Snead and Morley, 1981).The neuropharmacologic effects of GHB include increases in brainacetylcholine, increases in brain dopamine, inhibition ofGABA-ketoglutarate transaminase and depression of glucose utilizationbut not oxygen consumption in the brain. GHB is converted to succinateand then metabolized via the Krebs cycle. Clinical trials have shownthat GHB increases delta sleep and improves the continuity of sleep(Ladinsky et al., 1983; Anden and Stock, 1973; Stock et al., 1973;Laborit, 1973; Lapierre et al., 1988; Lapierre et al., 1990; Yamda etal., 1967; Grove-White and Kelman, 1971; Scharf, 1985).

[0006] GHB has typically been administered in clinical trials as an oralsolution (Lee, 1977; Mamelak, 1977; Hoes, 1980; Scharf, 1985; Scrima,1990; Gallimberti, 1992; Series, 1992; Lammers, 1993). GHB treatmentsubstantially reduces the signs and symptoms of narcolepsy, i.e. daytimesleepiness, cataplexy, sleep paralysis and hypnagogic hallucinations. Inaddition, GHB increases total sleep time and REM sleep, and it decreasesREM latency (Mamelak et al, 1973; Yamada et al., 1967; Bedard et al.,1989), reduces sleep apnea (Series et al, 1992; Scrima et al., 1987),and improves general anesthesia (Hasenbos and Gielen, 1985).

[0007] GHB has several clinical applications other than narcolepsy andsleep disorders. GHB has been reported to reduce alcohol craving, thenumber of daily drinks consumed, and the symptoms of alcohol withdrawalin patients (Gallimberti et al., 1989; Gallimberti et al., 1992; Gessaet al., 1992). GHB has been used to decrease the symptoms of opiatewithdrawal, including both heroin and methadone withdrawal (Gallimbertiet al, 1994; Gallimberti et al., 1993). It has analgesic effects thatmake it suitable as a pain reliever (U.S. Pat. No. 4,393,236).Intravenous administration of GHB has been reported to reduceintracranial pressure in patients (Strong, A. 1984). Also,administration of GHB was reported to increase growth hormone levels inpatients (Gerra et al, 1994; Oyama et al., 1970).

[0008] A good safety profile for GHB consumption, when used long termfor treatment of narcolepsy, has been reported. Patients have beensafely treated for many years with GHB without development of tolerance(Scharf, 1985). Clinical laboratory tests carried out periodically onmany patients have not indicated organ or other toxicities (Lammers,1993; Scrima, 1990; Scharf, 1985; Mamelack, 1977; Mamelak, 1979;Gallimberti, 1989; Gallimberti, 1992; Gessa, 1992). The side effects ofGHB treatment have been minimal in incidence and degree of severity,though they include sleepwalking, enuresis, headache, nausea anddizziness (Broughton and Mamelak, 1979; Mamelak et al., 1981; Mamelak etal., 1977; Scrima et al., 1989; Scrima et al., 1990; Scharf et al.,1985).

[0009] The pharmacokinetics of GHB have been investigated in alcoholdependent patients (Ferrara et al., 1992) and in normal healthy males(Palatini et al., 1993) after oral administration. GHB possesses a rapidonset and short pharmacological effect (Ferrara et al., 1992; Palatineet al., 1993; Lee, C., 1977; van der Bogert; Gallimberti, 1989;Gallimberti, 1992; Lettieri and Fung, 1978; Arena and Fung, 1980; Rothand Giarman, 1966; Vickers, 1969; Lee,: 1977). In alcohol dependentpatients, GHB absorption into and elimination from the systemiccirculation were fast processes. Virtually no unchanged drug could berecovered in the urine. There were preliminary indications that thepharmacokinetics of GHB might be non-linear or dose-dependent (Ferraraet al., 1992). In the healthy volunteers study, the pharmacokinetics ofthree rising GHB doses (12.5, 25, and 50 mg/kg) were investigated. Thesefindings indicate that both the oral absorption and eliminationprocesses of GHB were capacity-limited though the degree of dosedependency was moderate (Palatini et al., 1993).

[0010] Organic salts and amides of GHB have been produced to reduce thephysiological side effects of GHB (U.S. Pat. No. 5,380,937). Magnesiumand calcium salt have been produced to reduce the hygroscopic nature ofGHB or powdered forms (U.S. Pat. No. 4,393,236; British Patent No.922,029). However, problems with the storage of GHB solutions stillexist. GHB degrades into gamma-butyrolactone (GBL) and possibly otherdegradants in solution depending upon the pH and other factors. Also,the contamination by microorganisms in GHB solutions rapidly surpassacceptable limits, and preservatives can adversely affect the pH andthus, GHB's stability. As a chronically used product which requires highlevels of drug, the volume of a non-concentrated product creates costand handling issues. Thus, there is an immediate need for effectivesolutions of GHB that are stable to biological or chemical degradation.

SUMMARY OF THE INVENTION

[0011] The present invention overcomes deficiencies in the prior art byproviding compositions of GHB in an aqueous medium that are resistant tomicrobial growth. These compositions are also resistant to theuncontrolled degradation of GHB into GBL or other substances. Thecompositions of the present invention are stable compositions of GHBthat improve shelf-life; and provide a titratable formulation of GHB foreasy dose measurement. In addition, the concentrated solutions embodiedin this invention reduce shipping and storage requirements and allowpatients to carry more drugs for their convenience. The presentinvention provides methods to treat a number of conditions treatable byGHB, referred to herein as “therapeutic categories.” Therapeuticcategories for the present invention include, but are not limited to,sleeping disorders, drug abuse, alcohol and opiate withdrawal, a reducedlevel of growth hormone, anxiety, analgesia, effects in certainneurological disorders, such as Parkinson's Disease, depression, certainendocrine disturbances and tissue protection following hypoxia/anoxiasuch as in stroke or myocardial infarction, or an increased level ofintracranial pressure or other conditions treatable with GHB.

[0012] The invention first provides a pharmaceutical composition of GHBrendered chemically stable and/or resistant to microbial growth in anaqueous medium. Preferred GHB salts of the present invention includesodium, ammonium and calcium. As used herein in certain embodiments,“stable” may mean resistant to degradation of GHB into its known orunknown decomposition elements. The level of GBL that is acceptable canbe up to 0.1% of the formulation as per the ICH guidelines forshelf-life determination, As used herein in certain embodiments,“resistant to microbial growth” or “resistant to microbial challenge”means that the formulations meet the criteria set by the Food and DrugAdministration and the U.S. Pharmacopoeia for products made with aqueousbases or vehicles, which for bacteria means not less than a 1.0 logreduction from the initial count at 14 days, and no increase from the 14days count at 28 days, and for yeast and molds, no increase from theinitial calculated count at 14 and 28 days. As used herein in certainembodiments, an “aqueous medium” may mean a liquid comprising more thanabout 50% water. In certain preferred embodiments, an “aqueous medium”may be a solution, suspension, gel or emulsion of GHB, with a solutionof GHB being most preferred. Preferred gels are thixotropic gels.Compositions that are resistant to microbial growth are created bydissolving or mixing GHB in an aqueous medium to a concentration orcontent of greater than of about 150 mg/ml GHB to the maximal solubilityof GHB. The solubility of GHB is up to about 750 mg/ml at roomtemperature (20° C. to about 25° C.), however, heating the aqueousmedium during preparation up to 100° C. will increase GHB solubility toat least about 1000 mg/ml. A preferred concentration or content of GHBis about 500 mg/ml.

[0013] The amount of GHB that may be mixed or dissolved into an aqueousmedium and still be resistant to microbial growth depends upon the pH ofthe aqueous medium. In certain embodiments the presence of apreservative may allow the amount of GHB contained in the compositionsof the present invention to be increased and still maintain resistanceto chemical degradation and/or microbial growth. In one embodiment ofthe present invention, the pH of the aqueous medium of thepharmaceutical composition is about 3 to about 10.

[0014] In a preferred embodiment, the pH of said aqueous medium is about6 to about 7.5. The pH may be from about 3.0 to about 10.3, namely ofabout 3.0, about 3.1, about 3.2, about 3.3, about 3.4, about 3.5, about3.6, about 3.7, about 3.8, about 3.9, about 4.0, about 4.1, about 4.2,about 4.3, about 4.4, about 4.5, about 4.6, about 4.7, about 4.8, about4.9, about 5.0, about 5.1, about 5.2, about 5.3, about 5.4, about 5.5,about 5.6, about 5.7, about 5.8, about 5.9, about 6.0, about 6.1, about6.2, about 6.3, about 6.4, about 6.5, about 6.6, about 6.7, about 6.8,about 6.9, about 7.0, about 7.1, about 7.2, about 7.3, about 7.4, about7.5, about 7.6, about 7.7, about 7.8, about 7.9, about 8.0, about 8.1,about 8.2, about 8.3, about 8.4, about 8.5, about 8.6, about 8.7, about8.8, about 8.9, about 9.0, about 9.1, about 9.2, about 9.3, about 9.4,about 9.5, about 9.6, about 9.7, about 9.8, about 9.9, about 10.0, about10.1, about 10.2, or about 10.3, and all pH values between each of thelisted pH values, of the aqueous media. This will produce a GHBcomposition that is resistant to microbial growth as defined by the testdescribed herein. As used herein, the term “about” generally meanswithin about 10-20%.

[0015] These pH values will produce compositions resistant to microbialgrowth in an aqueous medium if the amount of GHB added, admixed, ordissolved is from above about 150 mg/ml to about 450 mg/ml, namely,above about 150 mg/ml, about 160 mg/ml, about 170 mg/ml, about 180mg/ml, about 190 mg/ml, about 200 mg/ml, about 210 mg/ml, about 220mg/ml, about 230 mg/ml, about 240 mg/ml, about 250 mg/ml, about 260mg/ml, about 270 mg/ml, about 280 mg/ml, about 290 mg/ml, about 300mg/ml, about 310 mg/ml, about 320 mg/ml, about 330 mg/ml, about 340mg/ml, about 350 mg/ml, about 360 mg/ml, about 370 mg/ml, about 380mg/ml, about 390 mg/ml, about 400 mg/ml, about 410 mg/ml, about 420mg/ml, about 430 mg/ml, about 440 mg/ml, to about 450 mg/ml, and allamounts of GHB between the values listed.

[0016] At the medium to high end of the concentration or content of GHBthat may be dissolved or mixed in the aqueous medium, the maximal pHthat may be used is reduced at room temperature. This is shown in FIG.1, a graphical presentation of acceptable formulation ranges. At aconcentration or content of about 450 mg/ml GHB, the pH may be of about3.9 to about 10.3. At a concentration or content of about 500 mg/ml GHB,the pH may be of about 4.75 to about 10.3. At a concentration or contentof about 600 mg/ml GHB, the pH may be of about 6.1 to about 10.3. At aconcentration or content of about 750 mg/ml GHB, the pH may be of about7.0 to about 10.3. Of course, all pH and concentration or content valuesin between each of the listed pH and concentration or content values areencompassed by the invention.

[0017] Certain embodiments may be selected as sub-ranges from thesevalues of GHB content and aqueous medium pH. For example, a specificembodiment may be selected as a content of about 170 mg/ml to about 440mg/ml GHB in an aqueous medium, at a pH range of about pH 5.5 to aboutpH 8.7. Another example of how a range may be selected in an embodimentwould be the selection of a content of about 155 mg/ml of GHB, which isa value between the above listed values, to a content of about 350 mg/mlof GHB, and the selection of a pH range of the aqueous medium, such as apH range of about 8.87, which is a value between the listed pH values,to a pH of about 8.93, which is another value between the listed valuesof pH. A third example of ranges that may be selected for a specificembodiment would be selection of a single content or concentration ofGHB, such as about 200 mg/ml of GHB, and the selection of a pH range,such as a pH of about 3.5 to about 8.2. A fourth example of ranges thatmay be selected for a specific embodiment would be selection of acontent or concentration of GHB over a range, such as about 300 mg/ml toabout 400 mg/ml, and the selection of a single pH value for the aqueousmedium, such as a pH of about 3. Another example of a range selected foran embodiment may be the selection of a single content or concentrationof GHB, such as 400 mg/ml GHB, and a single pH value of the aqueousmedium, such as pH 7.7.

[0018] Other examples of how a range of an embodiment of GHB content orconcentration may be selected include a range of GHB content orconcentration from about 200 mg/ml to about 460 mg/ml GHB, encompassingthe ranges for GHB described herein, and a range of pH for the aqueousmedium may be from about pH 4.3 to about pH 7, encompassing ranges forGHB in an aqueous medium at room temperature described herein. Anotherexample would be the selection of a range of GHB content orconcentration from about 153 mg/ml to about 750 mg/ml, and a pH range ofabout 7 to about 9, encompassing ranges between the listed values of GHBcontent and pH described herein. An example may be the selection as aGHB concentration or content of about 170 mg/ml to about 640 mg/ml in anaqueous medium, at a pH range of about pH 6.5 to about pH 7.7. Anotherexample of how a range may be selected in an embodiment would be acontent or concentration of about 185 mg/ml of GHB, which is a valuebetween the listed values, to a content or concentration of about 750mg/ml of GHB, at a pH range of about 7.87, which is a value between thelisted pH values, to a pH of about 8.91, which is another value betweenthe listed values of pH. An additional example of ranges that may beselected for a specific embodiment would be a content or concentrationof about 200 mg/ml of GHB at a pH of about 7 to about 8.2. Anotherexample of ranges that may be selected for a specific embodiment wouldbe a content or concentration of about 750 mg/ml to about 400 mg/ml at apH of about 7. Another example of ranges that may be selected for aspecific embodiment would be a content or concentration of about 300mg/ml to about 750 mg/ml at a pH of about 8.5 to about 7. Anotherexample of ranges that may be selected for a specific embodiment wouldbe a content or concentration of about 400 mg/ml to about 600 mg/ml at apH of about 9 to about 5.8. And so forth. Thus, all ranges of pH and GHBconcentration or content that can be selected from the values herein andas would be understood by those of ordinary skill in the art, areencompassed by the present invention.

[0019] The chemical stability of GHB is affected by pH, withcompositions of GHB in an aqueous medium with a pH below about 6 beingless effective in maintaining the chemical stability of GHB.Compositions with a pH of greater than about 6.0 are preferred toproduce chemically stable formulations of GHB. Thus, a preferred rangeto produce chemically stable GHB would be from about pH 6 to about pH 9.However, all concentrations or content of GHB in an aqueous medium, asdescribed herein, and as would be understood by those of ordinary skillin the art, may be selected to produce compositions of the presentinvention.

[0020] Additionally, the ranges described above are for a composition atroom temperature, which is defined herein as from about about 20° C. toabout 25° C., namely, about 20° C. about 21° C., about 22° C., about 23°C, about 24° C., to about 25° C. Within the values and ranges of pHdescribed above, the ranges of concentration or content of GHB mayincrease at temperatures greater than room temperature. Thus, themaximal content or concentration of GHB in an aqueous medium at atemperature of from about 26° C. to about 100° C., namely about 26° C.,about 27° C., about 28° C., about 29° C., about 30° C., about 31° C.,about 32° C., about 33° C., about 34° C., about 35° C., about 36° C.,about 37° C., about 38° C., about 39° C., about 40° C., about 41° C.,about 42° C., about 43° C., about 44° C., about 45° C., about 46° C.,about 47° C., about 48° C, about 49° C., about 50° C., about 51° C.,about 52° C., about 53° C., about 54° C., about 55° C., about 56° C.,about 57° C., about 58° C., about 59° C., about 60° C., about 61° C.,about 62° C., about 63° C., about 64° C., about 65° C., about 66° C.,about 67° C., about 68° C., about 69° C., about 70° C., about 71° C.,about 72° C., about 73° C., about 74° C., about 75° C., about 76° C.,about 77° C., about 78° C., about 79° C., about 80° C., about 81° C.,about 82° C., about 83° C., about 84° C., about 85° C., about 86° C.,about 87° C., about 88° C., about 89° C., about 90° C., about 91° C.,about 92° C., about 93° C., about 94° C., about 95° C., about 96° C.,about 97° C., about 98° C., about 99° C., to about 100° C. may be fromabout 750 to about 1 g/ml, namely to about 751 mg/ml, about 760 mg/ml,about 770 mg/ml, about 780 mg/ml, about 790 mg/ml, about 800 mg/ml,about 810 mg/ml, about 820 mg/ml, about 830 mg/ml, about 840 mg/ml,about 850 mg/ml, about 860 mg/ml, about 870 mg/ml, about 880 mg/ml,about 890 mg/ml, about 900 mg/ml, about 910 mg/ml, about 920 mg/ml,about 930 mg/ml, about 940 mg/ml, about 950 mg/ml, about 960 mg/ml,about 970 mg/ml, about 980 mg/ml, about 990 mg/ml, to about 1000 mg/ml.At temperatures below room temperature, the solubility of GHB maydecrease, and compositions at lower temperature and solubility of GHB atthe pH values and ranges described herein are also encompassed by theinvention. Additionally, differences of atmospheric pressure may alsoincrease or decrease the solubility of GHB within the ranges described,and embodiments of the invention with an increased or decreased contentof GHB due to changes in pressure are also encompassed by the invention.Of course, it is understood that the present invention encompassesembodiments of GHB concentration or content in an aqueous medium athigher or lower temperature within the values described herein, such asabout 980 mg/ml to about 200 mg/ml at 95° C. GHB at a pH of about 9 toabout 7.5. Or about 150 mg/ml GHB at about 17° C. at about pH 6 to aboutpH 7. And so forth. Thus, all ranges of pH and GHB content that can beselected at various temperatures and pressures from the values above,and as would be understood by those of ordinary skill in the art, areencompassed by the present invention.

[0021] In certain other embodiments of the present invention, thepharmaceutical composition may comprise a pH adjusting or bufferingagent. Such agents may be acids, bases, or combinations thereof. Incertain embodiments, the acid may be an organic acid, preferably acarboxylic acid or alphahydroxy carboxylic acid. In certain otherembodiments, the acid is selected from the group including, but notlimited to, acetic, acetylsalicylic, barbital, barbituric, benzoic,benzyl penicillin, boric, caffeine, carbonic, citric, dichloroacetic,ethylenediaminetetra-acetic acid (EDTA), formic, glycerophosphoric,glycine, lactic, malic, mandelic, monochloroacetic, oxalic,phenobarbital, phenol, picric, propionic, saccharin, salicylic, sodiumdihydrogen phosphate, succinic, sulfadiazine, sulfamerazine,sulfapyridine, sulfathiazole, tartaric, trichloroacetic, and the like,or inorganic acids such as hydrochloric, nitric, phosphoric or sulfuric,and the like. In a preferred embodiment, the acid is malic orhydrochloric acid. In certain other embodiments, the pH adjusting agentmay be a base selected from tile group including, but not limited to,acetanilide, ammonia, apomorphine, atropine, benzocaine, caffeine,calcium hydroxide, cocaine, codeine, ephedrine, morphine, papaverine,physostigmine, pilocarpine, potassium bicarbonate, potassium hydroxide,procaine, quinine, reserpine, sodium bicarbonate, sodium dihydrogenphosphate, sodium citrate, sodium taitrate, sodium carbonate, sodiumhydroxide, theobromine, thiourea or urea. In certain other embodiments,the pH adjusting agent may be a mixture of more than one acid and/ormore than one base. In other preferred embodiments, a weak acid and itsconjugate base are used to form a buffering agent to help stabilize thecomposition's pH.

[0022] In certain embodiments, the composition may contain one or moresalts. A “salt” is understood herein to mean certain embodiments to meana compound formed by the interaction of an acid and a base, the hydrogenatoms of the acid being replaced by the positive ion of the base.Various salts, including salts of GHB, are also encompassed by theinvention, particularly as pH adjusting or buffering agents.Pharmaceutically acceptable salts, include inorganic acids such as, forexample, hydrochloric or phosphoric acids, or such organic acids asmalic, acetic, oxalic, tartaric, mandelic, and the like. Salts formedcan also be derived from inorganic bases such as, for example, sodium,potassium, silicates, ammonium, calcium, or ferric hydroxides, and suchorganic bases as isopropylamine, trimethylamine, histidine, procaine andthe like. Alkali metal salts, such as lithium, potassium, sodium, andthe like may be used, preferably with an acid to form a pH adjustingagent. Other salts may comprise ammonium, calcium, magnesium and thelike. In one embodiment, a salt of GHB comprising an alkali metal may becombined with an acid to create a composition that achieves the desiredpH when admixed with an aqueous medium. In another embodiment, a weakbase may be combined with GHB to create a composition that achieves thedesired pH when admixed with an aqueous solution. Of course, other saltscan be formed from compounds disclosed herein, or as would be known toone of ordinary skill in the art, and all such salts are encompassed bythe invention.

[0023] In certain embodiments, excipients may be added to the invention.An “excipient” as used herein shall mean certain embodiments which aremore or less inert substances added as diluents or vehicles or to giveform or consistency when the remedy is in a solid form, though they maybe contained in liquid form preparations, e.g. syrups, aromatic powders,honey, and various elixirs. Excipients may also enhance resistance tomicrobial growth, and thus act as a preservative. Such excipientsinclude, but are not limited to, xylitol, mannitol, lactose, starch,magnesium stearate, sodium saccharine, cellulose, cellulose derivatives,magnesium carbonate and the like.

[0024] In certain embodiments, the pharmaceutical composition maycontain a preservative. A “preservative” is understood herein to meancertain embodiments which are substances added to inhibit chemicalchange or microbial action. Such preservatives may include, but are notlimited to, xylitol, sodium benzoate, methylparaben, propyl gallate BP,sorbic acid, chlorobutanol, dihydroacetic acid, monothioglycerol,potassium benzoate, propylparaben, benzoic acid, benzalkonium chloride,alcohol, benzoic acid, benzalkonium chloride, benzethonium chloride,benzyl alcohol, butylparaben, cetylpyridinium chloride, ethylenediamine,ethylpareben, ethyl vanillin, glycerin, hypophophorus acid,methylparaben, phenol, phenylethyl alcohol, phenymercuric nitrate,propylparaben, sassafras oil, sodium benzoate, sodium propionate,thimerosal and potassium sorbate. Preferred preservatives may beselected from the group comprising, but not limited to, xylitol, sodiumbenzoate, methylparaben, propylparaben and potassium sorbate. Xylitol isparticularly preferred in certain compositions of the invention, becauseit acts as an preservative and a sweetener, is a caries preventative, isless laxative than other sweeteners, and is recommended for diabetics.

[0025] In certain embodiments, the pharmaceutical composition may alsocontain an antioxidant. An “antioxidant” is understood herein to meancertain embodiments which are substances that inhibits oxidation. Suchantioxidants include, but are not limited to, asocrbyl palmitate,butylated hydroxyanisole, butylated hydroxytoluene, potassiummetabisulfite, sodium metabisulfite, anoxomer and maleic acid BP.

[0026] In certain embodiments, the pharmaceutical composition may alsocontain a flavoring agent. A “flavoring agent” is understood herein tomean certain embodiments which are substances that alters the flavor ofthe composition during oral consumption. A type of “flavoring agent”would be a sweetener. Preferred sweeteners or flavoring agents would bemicrobially non-metabolizable. Especially preferred sweeteners orflavoring agents would be carbohydrates such as xylitol and sorbitol.Such flavoring agents include, but are not limited to, acacia syrup,anethole, anise oil, aromatic elixir, benzaldehyde, benzaldehydeelixir-compound, caraway, caraway oil, cardamom oil, cardamom seed,cardamom spirit, cardamom tincture-compound, cherry juice, cherry syrup,cinnamon, cinnamon oil, cinnamon water, citric acid, citric acid syrup,clove oil, coca, coca syrup, coriander oil, dextrose, eriodictyon,eriodictyon fluidextract, eriodictyon syrup-aromatic, ethyl acetate,ethyl, vanillin, fennel oil, ginger, ginger fluidextract, gingeroleoresin, glucose, glycerin, glycyrrhiza, glycyrrhiza elixir,glycyrrhiza extract, glycyrrhiza extract-pure, glycyrrhiza fluidextract,glycyrrhiza syrup, honey, non-alcoholic elixir, lavender oil, citrusextract or oil, lemon oil, lemon tincture, mannitol, methyl salicylate,nutmeg oil, orange-bitter-elixir, orange-bitter-oil, orange flower oil,orange flower water, orange oil, orange peel-bitter,orange-peel-sweet-tincture, orange spirit-compound, compound, orangesyrup, peppermint, peppermint oil, peppermint spirit, peppermint water,phenylethyl alcohol, raspberry juice, raspberry syrup, rosemary oil,rose oil, rose water, saccharin, saccharin calcium, saccharin sodium,sarsaparilla syrup, sorbitol solution, spearmint, spearmint oil,sucrose, syrup, thyme oil, tolu balsam, tolu balsam syrup, vanilla,vanilla tincture, vanillin or wild cherry syrup.

[0027] Salts, excipients, pH adjusting agents such as acids, bases andbuffering agents, flavoring agents, and other agents that may becombined with the compositions of the present invention, or may be usedto prepare the compositions of the present invention, are well known inthe art, (see for example, “Remington's Pharmaceutical Sciences” 8th and15th Editions, and Nema et al., 1997, incorporated herein in theirentirety), and are encompassed by the invention.

[0028] In certain other embodiments, the pharmaceutical compositioncomprises GHB, a pH adjusting or buffering agent, and an aqueous medium,wherein the components are admixed (sequentially or simultaneously) toprepare said pharmaceutical composition. The pH adjusting or bufferingagent and aqueous medium may be any described herein.

[0029] The invention also provides a method of preparing a chemicallystable and microbial growth-resistant pharmaceutical composition for thetreatment of a condition responsive to GHB, comprising admixing GHB anda pH-adjusting or buffering agent in an aqueous medium. In certainembodiments, the method of preparing the pharmaceutical compositionfurther comprises admixing a preservative with the pharmaceuticalcomposition. Other components, such as flavoring agents, salts, and thelike, may be added to the composition. The pH adjusting or bufferingagent, aqueous medium, preservative, flavoring agents, salts, or otheringredient may be any described herein.

[0030] In certain other embodiments, the method of preparing thepharmaceutical composition comprises admixing GHB, a pH adjusting orbuffering agent, and an aqueous medium soon before administration to apatient suspected of having a condition responsive to GHB.

[0031] The invention also provides a method of treating any therapeuticcategory of disorder responsive to GHB, comprising administering to apatient suspected of having such a condition a therapeutic amount of apharmaceutical composition comprising chemically stable GHB (e.g. 1-10gms.) in an aqueous medium resistant to microbial growth. In certainembodiments, the method of treating a condition responsive to GHBcomprises a patient taking a first dosage of from about 0.1 g to about10 g, namely about 0.1, about 0.2 about 0.3 about 0.4, about 0.5, about0.6, about 0.7, about 0.8, about 0.9, about 1.0, about 1.1, about 1.2,about 1.3, about 1.4, about 1.5, about 1.6, about 1.7, about 1.8, about1.9, about 2.0, about 2.1, about 2.2, about 2.3, about 2.3, about 2.4,about 2.5, about 2.6, about 2.7, about 2.8, about 2.9, about 3.0, about3.1, about 3.2, about 3.3, about 3.4, about 3.5, about 3.6, about 3.7,about 3.8, about 3.9, about 4.0, about 4.1, about 4.2, about 4.3, about4.4, about 4.5, about 4.6, about 4.7, about 4.8, about 4.9, about 5.0,about 5.1, about 5.2, about 5.3, about 5.4, about 5.5, about 5.6, about5.7, about 5.8, about 5.9, about 6.0, about 6.1, about 6.2, about 6.3,about 6.4, about 6.5, about 6.6, about 6.7, about 6.8, about 6.9, about7.0, about 7.1, about 7.2, about 7.3, about 7.4, about 7.5, about 7.6,about 7.7, about 7.8, about 7.9, about 8.0, about 8.1, about 8.2, about8.3, about 8.4, about 8.5, about 8.6, about 8.7, about 8.8, about 8.9,about 9.0, about 9.1, about 9.2, about 9.3, about 9.4, about 9.5, about9.6, about 9.7, about 9.8, about 9.9, to about 10 grams of GHB, or asneeded by the patient as would be recognized by one of skill in the art.Of course, it will be understood that all values in between thoselisted, such as 9.45 grams, 6.32 grams, etc. may be administered, andthose values are encompassed well. In preferred embodiments, the firstdose is administered within an hour of sleep. In preferred embodiments,a second dose of GHB within the values described above may beadministered. This second dose is administered preferably within about2.0 to about 5.0 hrs, namely about 2.0, about 2.1, about 2.2, about 2.3,about 2.3, about 2.4, about 2.5, about 2.6, about 2.7, about 2.8, about2.9, about 3.0, about 3.1, about 3.2, about 3.3, about 3.4, about 3.5,about 3.6, about 3.7, about 3.8, about 3.9, about 4.0, about 4.1, about4.2, about 4.3,.about 4.4, about 4.5, about 4.6, about 4.7, about 4.8,about 4.9, to about 5.0 hours after the first dose, though it may beadministered at a time outside of the preferred range.

[0032] In certain embodiments, a second pharmaceutical may beadministered with the composition of GHB. Such a second pharmaceuticalmay be e.g., a stimulant administered within the same 24 hour period asthe first dose of GHB. The stimulant may be, e.g., but not limited to,methylphenidate or pemoline to counter the residual effects of GHBtreatment during periods of wakefulness. In certain embodiments, themethod of treating a sleep disorder may include the discontinuation ofother second pharmaceuticals used to control a sleep disorder. Suchsecond pharmaceuticals may include, but are not limited to, a tricyclicantidepressant.

[0033] In certain embodiments, the invention provides a method oftreating any appropriate therapeutic category of disorder, byadministration of GHB compositions of the present invention as describedabove for the treatment of sleep disorders. When GHB is used in methodsof treating any therapeutic category of disorder, the GHB composition ofthe present invention may be mixed with the aqueous medium, andoptionally pH adjusting or buffering agent or other additives, by thepatient or administrator soon before consumption. The patient mayprepare the composition within a few minutes to hours beforeadministration. Alternatively, one or more of the components may bepremixed for ready use. The components of the GHB composition of thepresent invention, GHB, an aqueous medium, pH adjusting or bufferingagent, excipients, preservatives, flavoring agents, and/or othercomponents or additives may be stored in a container means suitable toaid preservation. Preferably, the container means is in the form of aset. A “set” as used herein certain embodiments is one or morecomponents of the composition packaged in a container or other suitablestorage means.

[0034] The present invention also provides a set for the treatment of acondition responsive to GHB comprising, in suitable storage means, GHBand a pH adjusting or buffering agent. In certain embodiments, the GHBand the pH adjusting or buffering agent are separately packaged. Incertain other embodiments the GHB and the pH-adjusting or bufferingagent may be mixed. The set may contain an aqueous medium. In certainother embodiments, at least one component selected from the groupincluding, but not limited to, GHB, the pH-adjusting or buffering agentand/or an aqueous medium is separately packaged. In certain otherembodiments, at least two of the components selected from the groupcomprising GHB, a pH adjusting or buffering agent and an aqueous mediumare mixed together. In some embodiments, the set further contains apreservative. Such a set may have one, two, or more components from thegroup comprising GHB, a pH-adjusting or buffering agent, an aqueousmedium or a preservative packaged separately. Such a set may have two ormore components mixed together. Thus, both liquid and dry formulationsof GHB and other components may be packaged in a set for mixing beforeadministration, or one or more components may be premixed and packagedtogether with other components, or all the components may be premixedand packaged in a set.

[0035] It is understood that the compositions of the present invention,including those in a set, may be dispersed in a pharmaceuticallyacceptable carrier solution as described below. Such a solution would besterile or aseptic and may include water, co-solvent vehicle buffers,isotonic agents, pharmaceutical aids or other ingredients known to thoseof skill in the art that would cause no allergic or other harmfulreaction when administered to an animal or human subject. Therefore, thepresent invention may also be described as a pharmaceutical compositionof GHB with increased stability in a pharmaceutically acceptable carriersolution.

[0036] Unless defined otherwise, all technical and scientific terms usedherein have the same meaning as commonly understood by one of ordinaryskill in the art to which this invention belongs. Also as used herein,the term “a” “an” or “the” is understood to include the meaning “one ormore”. Although any methods and materials similar or equivalent to thosedescribed herein can be used in the practice or testing of the presentinvention, the preferred methods and materials are now described.

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The following drawings form part of the present specification andare included to further demonstrate certain aspects of the presentinvention. The invention may be better understood by reference to one ormore of these drawings in combination with the detailed description ofspecific embodiments presented herein.

[0038]FIG. 1. The Range of Gamma-Hydroxybutyrate's Resistance toMicrobial Growth and Chemical Stability in Aqueous Solution. Theordinate is the pH of solutions of GHB. The axis is the concentration(mg/ml) of GHB in aqueous solution. The region below the diagonal line[/] is the range of GHB solubility at room temperature. Greatersolubility can be achieved, up to 1 g/ml, by heating the solution up to100° C. Three solutions were adjusted with HCl and were susceptible tomicrobial growth (Δ). Two solutions were pH adjusted with malic acid andwere resistant to microbial growth (). Of these two solutions, the oneat pH 6 contained xylitol as an excipient. Three solutions were pHadjusted with hydrochloric acid and were resistant to microbial growth(▴). One solution was not pH adjusted and was susceptible to microbialgrowth (*).

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0039] I. Formulations of Gamma-Hydroxybutyrate

[0040] A. Microbial Growth and Gamma-Butyrolactone Formation

[0041] The present invention arises from the discovery of chemicallystable and microorganism resistant formulations of GHB in an aqueousmedium, preferably a solution, and the efficacy of these formulations inthe treatment of therapeutic categories of disorders, such as narcolepsyand other sleep disorders. Specifically, GHB is prepared at aconcentration greater than about 150 mg/ml in an aqueous medium, up tothe limits of GHB's solubility or retention in an aqueous medium, toproduce the compositions of the present invention.

[0042] The maximum solubility of GHB is affected by the pH of theaqueous medium. At about pH 4, the maximum amount of sodium-GHB that canbe dissolved is about 450 mg/ml. The value of pH that is conducive toGHB solubility increases, as is shown at FIG. 1, so that the minimal pHthat will dissolve 750 mg/ml GHB was found to be about pH 6.8. This isshown in Table 1. TABLE 1 Limits of Sodium Oxybate Solubility ID SodiumOxybate A Maximum Solubility pH of Solution Temperature B 450 mg/cc pH 4(HCl) 25° C 500 mg/cc pH 5 (HCl) 25° D 600 mg/cc pH 6 (HCl) 25° E 750mg/cc pH 6.8 (HCl) 25° F 750 mg/cc+ pH 10.3 25° G 1000 mg/cc pHunadjusted 65° Soluble, 25° Gel

[0043] The pH of the aqueous medium also affects the resistance of thecomposition to microbial growth at about 500 mg/ml GHB. GHB at thisconcentration in an aqueous medium that is between about pH 5 and pH 9is resistant to microbial growth, with compositions at about pH 6 toabout pH 7.5 being particularly resistant to microbial growth. However,at concentrations of GHB greater than about 750 mg/ml above about pH7.5, the resistance to microbial growth is reduced. This is shown atTable 2. TABLE 2 Microbial Challenge Data Summary ID Microbial H SodiumOxybate Concentration pH of Solution Challenge Result I 750 mg/cc 7.5(HCl) pass J 500 mg/cc 6.0 (HCl) pass K 500 mg/cc + Excipients 6.0(Malic Acid) pass (Xylitol) L 500 mg/cc 9.0 (HCl) pass (borderlineaspergillus) M 150 mg/cc (BDL 1995) 5.0 (HCl) fail (aspergillus only) N150 mg/cc (BDL 1995) 7.0 (HCl) fail (aspergillus & staph) O 150 mg/cc(BDL 1995) 3.0 (HCl) fail (aspergillus only) P 150 mg/cc (BDL 1995) 10.3(unadjusted) fail (aspergillus and staph) Q 500 mg/cc 6.0 (Malic Acid)discontinued R 500 mg/cc 7.5 (Malic Acid) pass S 500 mg/cc (May 1998)9.0 (Malic Acid) discontinued T 500 mg/cc (May 1998) 7.5 (HCl) pass* UOthers: 200 mg/cc-800 mg/cc 5.0-9.0 pending

[0044] For Category 1C Products Bacteria: Not less than 1.0 logreduction from the initial cout at 14 days, and no increase from the 14days' count at 28 days. Yeast and Molds: No increase from the initialcalculated count at 14 and 28 days.

[0045] The data from Table 1 and Table 2 are graphically shown inFIG. 1. The concentration of GHB in the composition, when evaluated inrelationship to the pH, affects the resistance of the GHB composition tomicrobial challenge. Compositions of GHB at or below 150 mg/ml arepoorly resistant to microbial challenge from a pH range of about pH 3 toabout pH 9. However, concentrations of GHB of greater than about 150mg/ml, up to about 1000 mg/ml of GHB, are believed to be suitablyresistant to microbial contamination at these pH ranges.

[0046] The chemical stability of GHB is affected by pH. Accordingly, themethod for preparing GHB, as described herein, particularly as disclosedin the specific examples, varies with pH. GBL begins to form if the pHis about 6 or less. Compositions with a pH of greater than about 6.0 arepreferred to produce chemically stable formulations of GHB. Thus, apreferred range to produce chemically stable GHB would be from about pH6 to about pH 9. However, any pH or range of pH values where aclinically acceptable amount of GBL is produced is also contemplated asbeing preferred, and is encompassed by the present invention. The rangeof GBL could be regulatorily broadened with availability of sufficienttoxicological data.

[0047] In certain embodiments of the invention, a pH-adjusting agent maybe added to the composition. The choice of a pH adjusting agent mayaffect the resistance to microbial challenge and/or the stability ofGHB, as measured by the reduction in assayable GHB. Compositions of GHB,pH adjusted with malic acid are resistant to both microbial growth andchemical degradation of GHB, and are preferred. Other pH adjusting orbuffering agents may be selected. Agents that adjust pH that areselected on this basis will undergo a taste testing study. However, anypH adjusting agent disclosed herein or as would be known to one ofordinary skill in the art is contemplated as being useful in theinvention. Of course, any salt, flavoring agent, excipient, or otherpharmaceutically acceptable addition described herein or as would beknown to one of ordinary skill in the art is contemplated as beinguseful in the invention.

[0048] Any of the above formulations may be prepared and/or packaged asa powdered or dry form for mixing with an aqueous medium before oraladministration, or they may be prepared in an aqueous medium andpackaged. After mixing with an aqueous medium, preferrably to prepare asolution, these formulations are resistant to both microbial growth andchemical conversion of GHB to GBL, thereby increasing the shelf-life oftherapeutic formulations of GHB in an aqueous medium. These formulationsthen provide an easily titratable liquid medium for measuring the dosageof GHB to be administered to a patient. Additional embodiments of thecomposition and methods of preparation are described below and in theexamples.

[0049] B. Pharmaceutical Compositions

[0050] 1. Pharmaceutically Acceptable Carriers

[0051] Aqueous compositions of the present invention comprise aneffective amount of GHB dissolved or dispersed in a pharmaceuticallyacceptable carrier and/or an aqueous medium. The phrases“pharmaceutically or pharmacologically acceptable” refer to molecularentities and compositions that do not produce an adverse, allergic orother untoward reaction when administered to an animal, or a human, asappropriate.

[0052] As used herein, “pharmaceutically acceptable carrier” includesany and all solvents, dispersion media, coatings, antibacterial andantifungal agents, isotonic and absorption delaying agents and the like.The use of such media and agents for pharmaceutical active substances iswell known in the art. Insofar as any conventional media or agent isincompatible with the active ingredient, its use in the therapeuticcompositions is not appropriate. Supplementary compatible activeingredients can be incorporated into the compositions. For humanadministration, preparations should meet sterility, pyrogenicity,general safety and purity standards as required by the Food and DrugAdministration (FDA).

[0053] The GHB may be lyophilized for more ready formulation into adesired vehicle where appropriate. The active compounds may beformulated for parenteral administration, e.g., formulated for injectionvia intravenous, intraarterial, intramuscular, sub-cutaneous,intralesional, intraperitoneal or other parenteral routes. Thepreparation of an aqueous composition that contains a GHB agent as anactive component or ingredient will be known to those of skill in theart in light of the present disclosure. Typically, such compositions canbe prepared as injectables, either as liquid solutions or suspensions.Solid forms suitable for using to prepare solutions or suspensions uponthe addition of a liquid prior to injection can also be prepared; andthe preparations can also be emulsified.

[0054] The pharmaceutical forms suitable for injectable use includesterile aqueous solutions or dispersions; formulations including, e.g.,aqueous propylene glycol; and sterile powders for the extemporaneouspreparation of sterile injectable solutions or dispersions. In all casesthe form must be sterile and must be fluid to the extent that easysyringability exists. It must be stable under the conditions ofmanufacture and storage and must be preserved against the contaminatingaction of microorganisms, such as bacteria and fungi.

[0055] Solutions of the active compounds as free acid orpharmacologically acceptable salts can be prepared in water suitablymixed with hydroxypropylcellulose and/or a pharmacueutically acceptablesurfactant. Dispersions can also be prepared in glycerol, liquidpolyethylene glycols, and mixtures thereof as well as in oils. Underordinary conditions of storage and use, these preparation may bestcontain a preservative to further prevent the growth of microorganisms.

[0056] A GHB composition of the present invention can be formulated intoa composition in a neutral or salt form. Such salts can be formed fromany of the acids and bases described herein particularly depending onthe particular GHB or GHB salt used, or as would be known to one ofordinary skill in the art.

[0057] The carrier can also be a solvent or dispersion mediumcontaining, for example, water, ethanol, polyol (for example, glycerol,propylene glycol, and liquid polyethylene glycol, or the like), suitablemixtures thereof, and vegetable oils. The proper fluidity can bemaintained, for example, by the use of a substance, such as lecithin(e.g. a coating), by the maintenance of the required particle size inthe case of dispersion and by the use of surfactants. The prevention ofthe action of microorganisms can be brought about by any of thepreservatives desribed herein, or as would be known to one of ordinaryskill in the art, including various antibacterial and antifungal agents,for example, parabens, chlorobutanol, phenol, sorbic acid, thimerosal,and the like. In many cases, it will be preferable to include isotonicagents, for example, sugars or sodium chloride. Prolonged absorption ofthe injectable compositions can be brought about by the use in thecompositions of agents delaying absorption, for example, aluminummonostearate.

[0058] Sterile injectable solutions are prepared by incorporating theactive compounds in the required amount in the appropriate solvent with,various of the other ingredients enumerated above, as required, followedby filtered sterilization. Generally, dispersions are prepared byincorporating the various sterilized active ingredients into a sterilevehicle which contains the basic dispersion medium and the requiredother ingredients from those enumerated above. In the case of sterilepowders for the preparation of sterile injectable solutions, thepreferred methods of preparation are vacuum-drying and freeze-dryingtechniques which yield a powder of the active ingredient plus anyadditional desired ingredient from a previously sterile-filteredsolution thereof. The preparation of more, or highly, concentratedsolutions for direct injection is also contemplated, where the use ofDMSO as solvent (although DMSO may not now be a permitted human drug) isenvisioned to result in extremely rapid penetration, delivering highconcentrations of the active agents to a small area.

[0059] Upon formulation, solutions will be administered in a mannercompatible with the dosage formulation and in such amount as istherapeutically effective. The formulations are easily administered in avariety of dosage forms, such as the type of injectable solutionsdescribed above, but drug release capsules and the like can also beemployed.

[0060] For parenteral administration in an aqueous solution, forexample, the solution should be suitably buffered if necessary and theliquid diluent first rendered isotonic with sufficient saline orglucose. These particular aqueous solutions are especially suitable forintravenous, intramuscular, subcutaneous and intraperitonealadministration. In this connection, sterile aqueous media which can beemployed will be known to those of skill in the art in light of thepresent disclosure. For example, one dosage could be dissolved in 1 mlof isotonic NaCl solution and either added to 1000 ml of fluid orinjected at the proposed site of infusion, (see for example,“Remington's Pharmaceutical Sciences” 15th Edition, pages 1035-1038 and1570-1580). Some variation in dosage will necessarily occur depending onthe condition of the subject being treated. The person responsible foradministration will, in any event, determine the appropriate dose forthe individual subject.

[0061] The active GHB may be formulated within a therapeutic mixture tocomprise about 100 to about 10,000 milligrams per dose. Multiple dosescan also be administered.

[0062] In addition to the compounds formulated for parenteraladministration, such as intravenous or intramuscular injection, otherpharmaceutically acceptable forms include, e.g., tablets or othersolids; liposomal formulations; time release capsules; and any otherform currently used, including cremes, which then may be admixed with anaqueous medium for oral administration.

[0063] One may also use nasal solutions or sprays, aerosols or inhalantsin the present invention. Nasal solutions are usually aqueous solutionsdesigned to be administered to the nasal passages in drops or sprays.Nasal solutions are prepared so that they are similar in many respectsto nasal secretions, so that normal ciliary action is maintained. Thus,the aqueous nasal solutions usually are isotonic and slightly bufferedto maintain a pH of 5.5 to 6.5, though other pH ranges disclosed hereinthe specific examples, such as pH 3 to about pH 9, or pH 6 to about 7.5,are contemplated. In addition, preservatives, similar to those used inophthalmic preparations, and appropriate drug stabilizers, if required,may be included in the formulation. Various commercial nasalpreparations are known and include, for example, antibiotics andantihistamines and are used for asthma prophylaxis.

[0064] The perferred oral formulations may include such normallyemployed excipients, as, for example, pharmaceutical grades of xylitol,mannitol, lactose, starch, magnesium stearate, sodium saccharin,cellulose, magnesium carbonate and the like. These compositions can takethe form of solutions, suspensions, tablets, pills, capsules, sustainedrelease formulations or powders to be admixed with an aqueous medium. Incertain defined embodiments, oral pharmaceutical compositions willcomprise an inert diluent or assimilable edible carrier, or they may beenclosed in hard or soft shell gelatin capsule, or they may becompressed into tablets, or the GHB may be packaged separately from orin combination with the excipients, salts, flavorings or any othercomponents described herein, to be admixed with an aqueous medium fororal or injectable formulations, or they may be incorporated directlywith the food (i.e. a beverage) of the diet.

[0065] For oral therapeutic administration, the active compounds may beincorporated with excipients and used in the form of tablets, buccaltablets or tabs, troches, capsules, elixirs, suspensions, syrups,wafers, and the like, to be admixed with an aqueous medium. Suchcompositions and preparations should contain at least 0.1% of activecompound. The percentage of the compositions and preparations.may, ofcourse, be varied and may conveniently be between about 2 to about 75%of the weight of the unit, or preferably between 25-60%. The amount ofactive compounds in such therapeutically useful compositions is suchthat a suitable dosage will be obtained.

[0066] The tablets, troches, pills, capsules and the like may alsocontain the following: a binder, nutural as gum tragacanth, acacia,cornstarch, or gelatin or synthetic as polyvinyl acetate; excipients,such as dicalcium phosphate;sa disintegrating agent, such as cornstarch, potato starch, alginic acid and the like; a lubricant, such asmagnesium stearate; and a sweetening agent, such as sucrose, lactose orsaccharin may be added or a natural or synthetic flavoring agent. Whenthe dosage unit form is a capsule for admixing with a specific volume ofan aqueous medium, it may contain, in addition to materials of the abovetype, a liquid carrier. Various other materials may be present ascoatings or to otherwise modify the physical form of the dosage unit.For instance, tablets, pills, or capsules may be coated with sugar,natural or synthetic polymers, or both. A syrup or elixir may containthe active compounds, sucrose as a sweetening agent, a preservative, adye and/or a flavoring.

[0067] Additionally, any excipient, salt, acid, pH-mediating, adjustingor buffering compound or agent, flavoring, solution, solvent,dispersion, glycerol, glycol, oil, antibacterial and antifungal agents,antibiotics and antihistamines, binders, disintegrating agents,lubricants, sweetening agents, or any other additive or ingredient fromthose enumerated above or in the examples, or in any pharmaceuticallyacceptable composition or carrier described herein, or as would be knownby one of skill in the art, is contemplated for use in aqueous mediumsor solid forms of the GHB compositions of the invention. One or more ofthese compositions may be packaged with GHB or packaged separately fromGHB prior to consumption. If packaged separately, useful compositions ofGHB may be obtained by mixing GHB with the other components with anaqueous medium prior to consumption. Such components may be packaged ina set, described below.

[0068] 2. Sets

[0069] Therapeutic sets of the present invention are sets comprisingGHB. Such sets will generally contain, in suitable container, apharmaceutically acceptable formulation of GHB. The set may have asingle container, or it may have distinct container for each component,or distinct container for various combinations of components.

[0070] When the components of the set are provided in one or more liquidformulations, the liquid formulation is an aqueous medium, with asterile aqueous solution being particularly preferred. The GHBcompositions may also be formulated into a syringeable composition. Inwhich case, the container means may itself be a syringe, pipette, vial,ampule or other such like apparatus, from which the formulation may beapplied to an infected area of the body, injected into an animal, oreven applied to and mixed with the other components of the set.

[0071] However, the components of the set may be provided as driedpowder(s). When reagents or components are provided as a dry powder, thepowder can be reconstituted by the addition of a suitable solvent. It isenvisioned that the solvent may also be provided in another containermeans.

[0072] The container means will generally include at least one vial,test tube, flask, bottle, pouch syringe or other container means, intowhich the GHB formulation or components thereof are placed, preferably,suitably allocated. The sets may also comprise a second container meansfor containing a sterile, pharmaceutically acceptable buffer or otherdiluent.

[0073] The sets of the present invention will also typically include ameans for containing the vials in close confinement for commercial sale,such as, e.g., injection or blow-molded plastic containers into whichthe desired vials are retained.

[0074] Irrespective of the number or type of containers, the sets of theinvention may also comprise, or be packaged with, an instrument forassisting with the injection/administration or placement of the GHBcomposition within the body of an animal. Such an instrument may be adrinking cup, syringe, pipette, or any such medically approved deliveryvehicle.

[0075] II. Methods of Treatment with the GHB Compositions

[0076] Because GHB has been shown to be effective in treating narcolepsyand sleep disorders (Lee, 1977; Mamelak, 1977; Hoes, 1980; Scharf, 1985;Scrima, 1990; Gallimberti, 1992; Series, 1992; Lammers, 1993), reducingalcohol craving and alcohol withdrawal symptoms, (Gallimberti et al.,1989; Gallimberti et al., 1992; Gessa et al., 1992), reducing opiatewithdrawal symptoms (Gallimberti et al, 1994; Gallimberti et al., 1993),reducing pain (U.S. Pat. No. 4,393,236), reducing intracranial pressurein patients (Strong, A. 1984), and increasing growth hormone levels inpatients (Gerra et al, 1994; Oyama et al., 1970), the formulations ofthe present invention are also contemplated to be useful in thetreatment of any of these disorders or conditions in patients. GHB hasalso been used alone as a narcotic in patients with a terminalcarcinomatous state. GHB has been used with other analgesics,neuroleptics, or with a subliminal barbiturate dose for use as ananesthesia. GHB has been used in closed cranio-cerebral trauma and as asoporific (U.S. Pat. No. 5,380,937). The inventors contemplate the useof the GHB compositions of the present invention as a narcotic,hypnotic, or as a soporific. The inventors also contemplate the use ofthe GHB compositions of the present invention in combination withanalgesics, neuroleptics or barbiturates for use as an anesthesia. TheGHB compositions of the present invention may be prepared andadministered by any of the means described herein, particularly thosedescribed in the section “Pharmaceutical Compositions” and the examples,or by any means as would be known to those of skill in the art.

[0077] The following examples are included to demonstrate preferredembodiments of the invention. It should be appreciated by those of skillin the art that the techniques disclosed in the examples which followrepresent techniques discovered by the inventor to function well in thepractice of the invention, and thus can be considered to constitutepreferred modes for its practice. However, those of skill in the artshould, in light of the present disclosure, appreciate that many changescan be made in the specific embodiments which are disclosed and stillobtain a like or similar result without departing from the spirit andscope of the invention.

EXAMPLE 1 Preferred Embodiments XYREM™ Clinical Trials

[0078] The inventors developed a liquid formulation composed of GHB,xylitol, and preservative in water (XYREM™). Subsequent instability ofthe preservative in this formulation and a desire to initiate clinicaltrials in a timely manner led to a change in the formulation to a foilpouch. One clinical trial utilized a twin-pouch dosage form, with oneside (pouch 1) of the foil packet containing GHB and the other side(pouch 2) containing the flavoring agents (Xylitol, [NF]; Malic Acid,NF;

[0079] Patients were instructed to open the twin-pouch with a scissors,empty the contents into a dosing cup, add 2 ounces of water, snap thelid on the dosing cup, shake to dissolve, and drink the entire contentsof the cup. Clinical trials conducted by the inventors have beenperformed using the twin-pouch dosage form.

[0080] However, the inventors have continued development of a liquidsolution and have now overcome inherent problems with particularformulations and/or preservatives. The inventors have converted patientscurrently enrolled in a GHB open-label trial to a liquid solutioncomposed of GHB, malic acid, and water—that is diluted with waterimmediately prior to oral administration.

[0081] The need for a liquid solution dosage form is further evidencedby the range of doses being used in a subsequent GHB open-label trial.Three sizes of pouches were prepared for the GHB open-label trial: 1.5grams, 3.0 grams, and 4.5 grams. The initial dose for all patients inthe GHB open-label trial was 6 grams of GHB nightly in divided doses.Dosage adjustments were permitted in the first two weeks of the trial asindicated for intolerance or lack of efficacy. The investigator waspermitted to decrease the dose of GHB to 3 grams or 4.5 grams, orincrease the dose to 7.5 grams or 9 grams nightly. After two weeks,further dosage adjustments were made if clinically indicated.

[0082] Thirty-five patients had their dose increased, and 16 patientshad their dose decreased. Patients in the lowest dose group weredisproportionately female and weighed 15 kg less than patients in theother two groups. Current dosing levels are noted below: TABLE 3 DosingLevels in the GHB Open-Label Trial 1.5 3.0 4.5 6.0 7.5 9.0 Total gramgram gram gram gram gram Number of  95 0 4 10 39 12 30 Patients Per Centof 100% 0% 4% 10% 41% 13% 32% Patients

[0083] To achieve these individualized doses, it has been necessary toprovide a combination of different dose strengths. This complexity wouldbe very difficult to achieve with a marketed product. In addition, amonth's supply of twin-pouches is quite bulky. A liquid formulationallows for ease in dosing adjustment with one dosage form. In addition“child-resistant” packaging has been developed with the liquidformulation.

[0084] A number of patients have also complained about the flavor withthe twin-pouches. As follow-up the inventors sent questionnaires toparticipants in the inventors' clinical trial, and performed tastetesting in normal volunteers. The questionnaire responses, taste testingresults, and the clinical experience in narcolepsy patients of the studyadministrator have all confirmed that unflavored solutions wereacceptable.

[0085] The concentration and volume of the GHB solution that the patientadministers will be the same irrespective of whether it is dissolvedfrom the pouch or diluted from the liquid. This is illustrated in Chart1 and Table 4: CHART 1 Comparison of Liquid Solution to Twin-Pouch

[0086] TABLE 4 Comparison of Liquid Solution to Twin-Pouch Twin-PouchLiquid Solution Amount of GHB 3 grams (1 pouch) 3 grams (6 mL) InactiveComponents malic acid malic acid xylitol lemon/lime flavor orange flavorFinal Concentration 50 mg/mL 50 mg/mL* Final Volume 60 mL 60 mL

[0087] Apart from the elimination of the sweetener (xylitol) andflavoring, the two formulations result in identical solutions.

[0088] Conclusions

[0089] The concentration and volume of the GHB solution that the patientadministers is the same irrespective of whether it is dissolved from thepouch or diluted from the liquid. Either method may be used to produceacceptably stable solutions of GHB.

EXAMPLE 2 Preferred Embodiments Self Preserving Formulations ofGamma-Hydroxybutyrate Summary of Formulation Studies—Liquid XYREM™

[0090] I. Maximum Solubility Range

[0091] As seen in FIG. 1 and Table 1, the solubility of GHB varies withpH levels at room temerature (25° C.). Additional amounts of GHB can besolubilized in a gel if heat is applied, in which case a 1000 mg/mlconcentration can be achieved. The inventors contemplate that though theconcentrations or contents of GHB shown in FIG. 1 and Table 1 arepreferred for use, due to the ease of preparing and consuming unheatedpreparations, higher concentrations of GHB in aqueous medium may also bemade, up to 1000 mg/ml.

[0092] II. Microbial Testing

[0093] The inventors used a three factor analysis involving pH,concentrations of GHB and the pH adjuster used. As seen in FIG. 1, andTable 2, unacceptably low resistance to microbial challenge was seen at150 mg/ml GHB at pH 3, 5, 7, and 9.0, using HCl as the pH adjustingagent. 150 mg/ml GHB at pH 10.3 without a pH adjusting agent also provedunacceptably resistant to microbial challenge. Borderline acceptablemicrobial preservativeness was seen in a solution pH adjusted with HClat 500 mg/ml GHB at pH 9. At a concentration of 500 mg/ml at pH 6.0 or7.5, adjusted with either malic acid or HCl, and 500 mg/ml at pH 9.0adjusted with HCl, the formulation is very effective in a microbialchallenge test. The inventors contemplate that a concentration ofgreater than about 150 mg/ml of GHB, up to the maximal solubility inaqueous solution of GHB, will be suitably resistant to microbialchallenge from about pH 3 to pH 10.3. Preferably, the aqueous mediumwill contain a pH-adjusting or buffering agent.

[0094] III. Gamma-Butyrolactone Degradation Range

[0095] GBL begins to form if the pH is about 6 or less with theformulation tested thus far.

[0096] A. Liquid Formulation Development

[0097] The objective of these experiments was to develop a commercialformulation for sodium gamma hydroxybutyric acid. The initialformulation for sodium gamma hydroxybutyric acid (GHB) was intended tobe an aqueous liquid formulation containing 150 mg/mL GHB, preservativesand flavoring agents. To develop this formulation, studies wereconducted to establish the: solubility of the drug in water and as afunction of pH, type and concentrations of suitable preservatives, typeand concentrations of flavor ingredients, and stability of theformulations.

[0098] 1. Solubility

[0099] The feasibility of preparing formulations containing 150 mg/mL ofGHB at pH 3, 5 and 7 was established. Solutions containing 150 mg/mL GHBwere prepared. The initial pH was greater than pH 7.5 and the final pHwas adjusted to 3, 5 or 7 with hydrochloric acid. The solutions wereobserved for precipitation and assayed by HPLC for GHB content. Theresults showed that no precipitation was observed and the drugconcentration was found to be 150 mg/mL by HPLC. This information wasused as the basis for additional formulation development studies.

[0100] 2. Preservatives

[0101] Preservative effectiveness studies were conducted to identify asuitable preservative for the GHB liquid formulation. The followingformulations shown in Table 5 were prepared and tested usingStaphylococcus attreus (ATCC #6538), Pseudomonas aeruginosa (ATCC #9027)and Aspergillus niger (ATCC #16404). TABLE 5 Liquid Formulations Used inPreservative Effectiveness Testing Formu- Sodium Methylparaben Potassiumlation pH Benzoate Propylparaben Sorbate Control 1 3 X 2 5 X 3 7 X 4 3 X5 5 X 6 7 X 7 3 X 8 5 X 9 7 X 10 3 X 11 5 X 12 7 X 13 no pH X adjustment

[0102] The preservative used in each formulation is marked with an X.The results showed that formulations #3, 4, 6 and 9 reduced all threechallenge microorganisms by >99.99% in 48 h of contact time.Formulations #1, 5 and 7 reduced all three challenge microorganismby >99.99% in 7 days of contact time. Formulations #2, 8, 10, 11, 12 and13 did not reduce Aspergillus niger mold to >99.99%, although somereduction occurred in 7 days of contact time. Controls #10, 11, 12 and13 demonstrated activity against Pseudomonas aeruginosa.

[0103] 3. Stability

[0104] Based on the results of the preservative effectiveness testing,five formulations were selected for stability testing. Table 6 shows thecomposition of the formulations. TABLE 6 Liquid Formulations Used inInformal Stability Program Chemical 1 2 3 4 5 Potassium 0.4 gm 0.4 gmSorbate Sodium 1.0 gm Benzoate Methyl- 0.36 gm 0.36 gm paraben Propyl-0.04 gm 0.04 gm paraben GHB 30 gm 30 gm 30 gm 30 gm 30 gm Xylitol 40 gm40 gm 40 gm 40 gm 40 gm Water q.s. 200 mL 200 mL 200 mL 200 mL 200 mLInitial pH 8.68 8.68 9.30 7.75 7.75 Formulation 3.01 5.00 3.00 2.98 4.98Adjusted pH

[0105] The formulations were packaged in 125 mL, amber PET bottles withsafety lined child-resistant caps and stored upright and inverted at 60°C., 40° C./75% relative humidity (RH) and 25° C./60% relative humidity.Samples were removed from the stability chambers after 1, 2 and 3 monthsand assayed by high performance liquid chromatography (HPLC) for GHBcontent. Appearance and pH were also monitored.

[0106] Table 7 shows the results for the 3 month time point. Samplesstored at 60° C. changed color but samples at all other conditionsremained unchanged in color.

[0107] The pH of all formulations migrated upward over the three monthstability period 60C. The percent increase in pH from initial to 3months, was greater for the formulations which were initially adjustedto lower values.

[0108] For example, the migration of pH in formulations 1,3 and 4(adjusted down to pH 3) were 21-30 percent across all conditions inthree months. The migration of pH in formulations 2 and 5 (adjusted downto pH5) were 4.2-12 percent across all conditions in 3 months.Maintenance of pH becomes important for long term storage sincepreservatives are known to degrade in formulations having pH levelsabove approximately pH 6.

[0109] Additionally, development of flavor systems to mask the negativetaste of perservatives is difficult. TABLE 7 Results of LiquidFormulation Informal Stability Study at Three Months 25° C./ 25° C./ 40°C./ 40° C./ Formulation # 60% RH 60% RH 75% RH 75% RH 60° C. (See Table6) Attribute Upright Inverted Upright Inverted Upright 1 % t = 0 100.7101.6 101.2 NA NA Potassium pH 3.63 3.64 3.84 3.82 3.91 Sorbate (pH3)Appearance clear, clear, clear, clear, clear, light at 3 monthscolorless colorless colorless colorless yellow storage 2 % t = 0* 102.1105.0 104.0 102.0 99.6 Potassium pH 5.21 5.28 5.55 5.56 5.61 Sorbate(pH5) Appearance clear, clear, clear, clear, clear, light colorlesscolorless colorless colorless brown 3 % t = 0 102.4 104.1 99.1 102.697.0 Sodium pH 3.60 3.74 3.78 3.75 3.79 Benzoate (pH3) Appearance clear,clear, clear, clear, clear, colorless colorless colorless colorlesscolorless 4 % t = 0 101.5 102.7 100.6 101.2 93.7 4 Methyl & pH 3.63 3.713.81 3.80 3.83 Propyl Parabense Appearance clear, clear, clear, clear,clear, (pH3) colorless colorless colorless colorless colorless 5 % t = 0103.1 105.8 101.9 103.1 95.6 4 methyl & pH 5.22 5.55 5.55 5.56 5.60Propyl Prabens Appearance clear, clear, clear, clear, clear, light (pH5)colorless colorless colorless colorless yellow

[0110] 4. Liquid Formulation Organoleptic Testing

[0111] Based on the above stability data and preservative effectivenesstesting, a pH 5 formulation containing potassium sorbate was selected asthe primary base formulation for flavor system development andorganoleptic testing. A pH 3 formulation containing potassium sorbatewas selected as the back-up formulation.

[0112] B. Dry Powder Formulation Development

[0113] Developing a flavor system for the primary and back-up liquidformulations proved to be difficult and a decision was made to develop adry powder formulation for reconstitution with water before consumption.This approach removed the need for a preservative system, therequirement to adjust pH to levels below pH6, and allowed thedevelopment of a suitable flavor system.

[0114] 1. Dry Powder Formulation Organoleptic Testing

[0115] To develop a flavor system for the powder formulation, severalparameters were evaluated. The flavor attributes of a GHB solution wascharacterized by a professional sensory panel. A mimic base containingsimilar sensory properties as a GHB solution for flavor system wasdeveloped. Generally Recognized As Safe (GRAS) excipients for flavorsystem development were selected. Different excipients (flavorings,sweeteners, acidulants and flow agents) in the mimic base were screened.Three flavor systems for the focus group test were selected. A preferredflavor system was optimized based on comments obtained from the focusgroup testing. This final formulation with GHB was optimized.

[0116] Based on the above activities, the following formulations inTable 8 were selected for stability studies: TABLE 8 Composition ofPrototype Dry Powder Formulation Composition Ingredient (grams) PurposeGHB 3 Active Xylitol 5.5 non-cariogenic sweetener Malic acid 0.2Acidulant Flavor 1 0.2 Flavor ingredient Flavor 2 0.04 Flavor ingredientSilicon Dioxide 0.03 Flow enhancer (Cab-O-Sil ®)

[0117] 2. Dry Powder Formulation Stability

[0118] A study was initiated to evaluate the stability of the aboveprototype formulation in two types of foil packages (high and moderatemoisture resistant) as well as the stability of GHB alone in one type offoil package (high moisture resistant). Table 9 shows the Lots that wereplaced on stability. The foil packages were a high moisture resistantpouch and a moderate moisture resistant pouch. The study protocol, Table10, required the samples to be stored at 40±2° C./75±5% relativehumidity for six months, and 25±2° C./60±5% relative humidity for 12months. Table 11 shows the tests, methods, number of packets/test andspecifications for the study. TABLE 9 Dry Powder Informal StabilityStudy Package Composition Manufacture Package Lot Number DateConfiguration Special Comments SPO #8018 A Oct. 6, 1995 Foil PacketModerate moisture resistant pouch. SPO #8018 B Oct. 6, 1995 Foil PacketHighest moisture protection pouch. SPO #8018 C Oct. 6, 1995 Foil PacketDrug substance only. Highest moisture protection pouch.

[0119] TABLE 10 Dry Powder Informal Stability Study Protocol StabilityTime in Months Storage Conditions 0 1 2 3 6 9 12 40 ± 2° C./75% ± 5% RHX X X X 25 ± 2° C./60% ± 5% RH X X C C R R R

[0120] TABLE 11 Dry Powder Informal Stability Tests and SpecificationsPackets/ Test Method Test Specification Limits Appearance Visual UseHPLC White to off-white free Dry Material flowing powder AppearanceVisual Use HPLC Cloudy, off-white solution Reconstituted with visibleparticulates Material Rate of Visual Use HPLC Material should dissolveDissolution completely in five min with mixing Odor Olfactory Use HPLCCharacteristic Lemon/Lime odor Assay: GHB HPLC 3 90.0%-110.0% Assay:Malic HPLC Use HPLC 90.0%-110.0% Acid Impurities/ HPLC Use HPLC Not morethan 1% for any Degradants individual impurity/degra- dant and Not morethan 3% total impurity/degradants Vacuum Leak Visual 3 No Appearance ofLeaking test pH USP <791> Use HPLC For Information Moisture Karl Fisher3 Report Value - to be determined

[0121] After two months at 40±2° C./75±5% relative humidity, the potency(% label claim) of Lots SPO 8018A and SPO 8018B was less than 94.0%, thelower limit of the specification, whereas Lot SPO 8018C showed no lossin potency. Lots 8018A and 8018B showed approximately 96% potenciesafter 2 months at 25° C.±2° C./65%±5% relative humidity. Lot SPO 8018Cagain showed no loss in potency at this lower storage condition.

[0122] 3. Appearance

[0123] After 2 months at 40° C.±2° C./75%±5% relative humidity, Lots SPO8018A and SPO 8018B showed significant melting, whereas Lot 8018C showedno melting. Lots SPO 8018A and SPO 8018B also showed partial meltingafter 2 months at 25° C.±2° C.,/65%±5% relative humidity. Lot SPO 8018Cagain showed no evidence of melting at this lower storage condition.

[0124] Based on the physical changes in state observed during thestability studies, it was apparent that a solid state interactionbetween GHB and the excipient blend had occurred. Since xylitol made upthe majority of the excipient blend, it was assumed that xylitol was theprimary source of the drug-excipient interaction. An alternativehypothesis was also proposed, based on the possibility that the packagewas mediating the interaction between GHB and xylitol. Three studieswere initiated to test these hypotheses.

[0125] 4. Stability of GHB Solids in a Set Container-System

[0126] In the first study, the samples that were stored at 25±2°C./60±5% relative humidity were transferred to glass vials and thenstored at 40±2° C./7±5% relative humidity. In the second study, mixturesof GHB and xylitol were gently rubbed between sheets of different typesof foil packaging. The mixtures were observed for changes in physicalappearance. In the third study, different mixtures of GHB and xylitolwere prepared. Differential Scanning Calorimetry (DSC) thermograms werethen done to look for changes in the thermograms. The results of thesestudies are summarized below.

[0127] Transfer to Glass: Samples of Lot 8018A and Lot 8018C that werepreviously stored at 25±2° C./60±5% relative humidity were transferredto amber screw cap vials and stored at 40±2° C./75±5% relative humidity.Analyses similar to those shown in Table 6 were done. After I month, thepotency of Lot 8018A was 94.6% whereas the potency of Lot 8018C (GHBonly) was 100%. In addition, Lot 8018A also showed evidence of melting.The results supported the hypothesis that GHB and xylitol wereinteracting in the solid state and the interaction appeared to beindependent of packaging.

[0128] Foil Study: Mixtures of GHB and xylitol were placed betweenfolded sheets of several different foil packaging materials. Slightadhesion of the mixed granules with the foil lining was observed for allof the foils examined. No direct evidence of melting was observed,however, even when excessive force was applied to the outer foilsurfaces. This data suggests that the packaging material was notresponsible for the solid state interaction observed during thestability studies.

[0129] DSC thermographs were obtained for samples of GHB/xylitolcontaining GHB:xylitol mixtures of 33:66, 45:55 and 55 percent 45respectively. The scans were conducted at a scan rate of 10° C./min. Thethermograms showed that the sample containing GHB:xylitol 33:66 showed abroad endothermic transition starting at 35° C. -40° C. Samples withhigher ratios of GHB:xylitol also showed broad endothermic transitionsthat started at temperatures of 45° C.-50° C. The changes seen in thethermograms supported the hypothesis that a solid state interaction maybe occurring between GHB and xylitol that resulted in low potencies forformulations containing mixtures of these two agents.

[0130] As a result of the changes seen in the DSC thermograms fordifferent mixtures of GHB:xylitol, a study was initiated to investigatethe stability of a formulation containing GHB:xylitol excipient blend55:45. A formulation containing GHB:xylitol excipient blend 33:66 wasused as a control sample. The formulations were packaged in glass vialsand stored at 50° C., 40±2° C./75±5% relative humidity and 25±2°C./60±5% relative humidity. The appearance and potency of theformulations were monitored through analyses of stability samples. Thestability study also showed potency losses after 1 month at 40° C.±2°C./75% ±5% relative humidity with both the 50/50 GHB:xylitol ratio aswell as the original 33/66 ratio formulation. Partial evidence ofmelting was also observed in both formulations.

[0131] Studies with mixtures of GHB:xylitol excipient blend indicatedthat the mixture was incompatible in the solid state. However, whenprepared as an aqueous solution, these mixtures were chemicallycompatible. Using this information, a decision was made to package theGHB formulation in dual pouches; one pouch containing GHB alone and theother containing a mixture of xylitol and the other flavor ingredients.The formulation will contain equal amounts of GHB and the excipientblend. This product will be prepared, packaged, and may be checked forstability.

EXAMPLE 3 The Pharmacokinetics of Gamma-Hydroxybutyrate

[0132] I. Study Objectives

[0133] The objective of this study was to assess the pharmacokinetics ofGHB after oral administration of two consecutive single doses of GHB (3g/dose; patients generally ingested the first dose of this medicationprior to bedtime and the second dose from 2.5 to 4.0 h later) tonarcoleptic patients who are maintained on a chronic regimen of GHB.

[0134] II. Study Design

[0135] This pharmacokinetic study was conducted as an open-label,single-center investigation in 6 narcoleptic patients. The study designis summarized as follows: TABLE 12 Screening/Washout=> Treatment/BloodSampling=> Follow-up (1 or more days to (Two 3 g GHB oral doses, 4 h(Within 48 h after dosing; washout, at apart; 21 blood samples) lastblood sample) least 8 h

[0136] Narcoleptic patients, 18 years of age or older, who volunteeredfor this study were screened at least one day prior to the treatmentphase. Each patient was determined to be in stable health and evaluatedfor the presence of narcolepsy, defined for the purposes of this exampleas one or more years of medical history of narcolepsy as evidenced by arecent nocturnal polysomnogram (PSG) and a valid score from a MultipleSleep Latency Test (MSLT).

[0137] Patients maintained on GHB were allowed to participate. Thesepatients had been weaned from antidepressants, hypnotics, sedatives,antihistamines, clonidine, and anticonvulsants though a stable regimenof methylphenidate (immediate release or sustained release) was allowed.Each patient passed a pre-study physical examination (which includedhematology, blood chemistry, urinalysis, and vital signs measurements)prior to the commencement of the treatment phase.

[0138] Before oral administration of the first GHB dose, an indwellingcatheter was placed in an arm vein and a baseline blood sample wascollected. Each patient then ingested a 3 g dose of GHB before bedtime.Another 3 g GHB dose was administered 4 h after the first dose.Twenty-one sequential blood samples were collected over 12 h (startingat 10 min after the first dose and ending at 8 h after the second dose).Upon completion of the treatment phase, a follow-up physical examinationwhich included the measurement of vital signs was performed on eachpatient within 48 h after the last blood sample. A detailed descriptionof the trial methodology is presented in Section IV.

[0139] III. Inclusion Criteria

[0140] Patients were included in the study if they: had signed aninformed consent prior to beginning protocol required procedures; hadnot participated in such a study at an earlier date; were willing andable to complete the entire study as described in the protocol; were 18years of age or older at study entry; had not taken any investigationaltherapy other than GHB within the 30-day period prior to screening forthis study; had an established diagnosis of narcolepsy for at least oneyear with documentation from a qualified laboratory by a nocturnalpolysomnogram (PSG) and a Multiple Sleep Latency Test (MSLT) whichdemonstrated mean sleep latency to be less than 5 min and REM onset inat least 2 of 5 naps; had not been diagnosed with uncontrolled sleepapnea syndrome, defined as a sleep Apnea Index of 5 or an Apnea HypopneaIndex (AHI) greater than 10 per hour or any other cause of daytimesleepiness; and were free of any medication for their narcolepsy(including hypnotics, sedatives, antidepressants, antihistamines,clonidine, and anticonvulsants) other than GHB and methylphenidate (IRor SR). Patients admitted to this study if they were not experiencingunstable cardiovascular, endocrine, gastrointestinal, hematologic,hepatic, immunologic, metabolic, neurological, pulmonary, and/or renaldisease which would place them at risk during the study or compromisethe protocol objective; did not have neurological or psychiatricdisorders (including transient ischemic attacks, epilepsy, or multiplesclerosis) which, in the investigator's opinion, would preclude thepatients' participation and completion of this study; did not have acurrent or recent (within one year) history of alcohol or drug abuse;did not have a serum creatinine greater than 2.0 mg/dL, abnormal liverfunction tests (SGOT or SGPT more than twice the upper limit of normal,or serum bilirubin more than 1.5 times normal). Female patients wereentered into the study if they were either post-menopausal (i.e. nomenstrual period for a minimum of 6 months), surgically sterilized orprovided evidence of effective birth control. Females of childbearingpotential must agree to continue to use an IUD, diaphragm, or take theiroral contraceptives for the duration of the study. Female patients ofchildbearing potential must have a negative pregnancy test upon entryinto the study.

[0141] IV. Trial Methodology

[0142] A time and events schedule is presented in Table 12.

[0143] A. Screening Period/Washout

[0144] Six narcoleptic patients who were chronically being treated withGHB were recruited to participate in this pharmacokinetic study. Thescreening period was at least one day prior to the treatment phase.During the screening period each patient completed the followingprocedures for the assessment of their physical condition: medicalhistory evaluation; physical examination evaluation; clinical laboratoryevaluation; inclusion criteria review. Each patient's GHB andmethylphenidate regimen also were recorded on an appropriate case reportform (CRF). The investigator also ensured that there was at least an8-hour washout period for GHB prior to the treatment.

[0145] B. Treatment Period/Blood Samples Collection

[0146] All patients were hospitalized from approximately four hoursprior to first GHB dosing (around 6 p.m.) until the end of the treatmentperiod (around 10 a.m. the next morning). Patients ate their dinner atthe clinical research unit soon after arrival and fasted until breakfastnext morning. At least three hours elapsed between the completion ofdinner and the administration of the first GHB dose. An indwellingcatheter was placed in an arm vein of each patient for blood sampling atapproximately 30 min and 1 h before the first GHB dose and a baselineblood sample (5 mL) was collected.

[0147] The first GHB dose (3 g) was administered at around 10 p.m.Dosing of individual patients were staggered. The second GHB dose wasadministered at 4 h after the first GHB dose (i.e. immediately after the4 h blood sample). The exact dosing times in each patient were recordedon appropriate CRF pages. Blood samples (5 mL each) were collectedthrough the indwelling catheter into heparinized tubes at 0.2, 0.4, 0.6,0.8, 1, 1.5, 2, 3, 4, 4.2, 4.4, 4.6, 4,8, 5, 5.5, 5, 7, 8, 10, and 12 hafter the first GHB dose. Blood samples were processed according to theprocedures described herein. Patients were monitored for adverseexperiences throughout the study according to the specific procedures.

[0148] C. Follow-Up

[0149] Follow-up occurred within 48 h after the last blood sample hadbeen collected. An abbreviated physical examination which included vitalsigns measurement was performed. Adverse experiences and concomitantmedication use, if any, were assessed. Any ongoing adverse experiencesand clinically important findings in a patient were followed to theinvestigator's and/or sponsor's satisfaction before the patient wasdischarged from the study.

[0150] D. Methods of Assessment

[0151] 1. Medical History

[0152] The medical history was recorded during the screening period. Thehistory included gender, age, race, height, prior reaction to drugs, useof alcohol and tobacco, history and treatment, if any, of cardiovascularpulmonary, gastrointestinal, hepatic, renal, immunologic, neurological,or psychiatric diseases and confirmation of inclusion criteria.

[0153] 2. Physical Examination

[0154] Physical Examination included body system review as well asmeasurement of body weight and vital signs and a neurologicalexamination.

[0155] 3. Vital Signs

[0156] Vital signs measurements included recording of blood pressure,heart rate, respiration, and body temperature.

[0157] 4. Clinical Laboratory

[0158] All clinical laboratory tests were performed at a locallaboratory. The laboratory tests and analysis were required of eachpatient included: hematology, including hemoglobin, hematocrit, redblood cell count, white blood cell count and differential; fasting bloodchemistries included blood urea nitrogen (BUN), uric acid, glucose,creatinine, calcium, phosphorus, total protein, albumin, sodium,potassium, SCOT (AST), SGPT (ALT), alkaline phosphatase, lactatedehydrogenase (LDH), and total bilirubin; midstream catch urinalysisincluded specific gravity, pH, protein, occult blood, ketones andglucose by dipstick determination as well as a microscopic examinationof urine sediment for RBC, WBC, epithelial cells or casts or crystals;and a urine pregnancy test, if applicable. Any laboratory parameter thatwas out of range and considered clinically significant excluded thepatient from participation in this study. The investigator would providean explanation of all observations that were significantly outside thereference range.

[0159] 5. Concomitant Medication

[0160] The continued use of a fixed dose of methylphenidate immediaterelease or sustained release (IR or SR) is acceptable. Themethylphenidate regimen was recorded on the appropriate case reportform.

[0161] 6. Adverse Experiences

[0162] An adverse experience are any undesirable event experienced by apatient or volunteer whether or not considered drug-related by theinvestigator. An undesirable event can be, but is not limited to,subjective symptoms experienced by a patient or, objective findings suchas significant clinical laboratory abnormalities. Adverse experience isconsidered synonymous with the term “adverse event”.

[0163] The investigators report in detail all adverse experiences andsymptoms that occurred during or following the course of trial drugadministration for up to 2 days. Included in the description was thenature of the sign or symptom; the date of onset; date or resolution(duration); the severity; the relationship to trial treatment or othertherapy; the action taken, if any; and the outcome.

[0164] A serious adverse experience is defined as one that is fatal,life threatening, permanently disabling, or which results in or prolongshospitalization. In addition, overdose, congenital anomaly andoccurrences of malignancy are always considered to be serious adverseexperiences. An unexpected adverse experience is one not previouslyreported.

[0165] Any serious or unexpected adverse experience (including death)due to any cause which occurs during the course of this investigation,whether or not it is related to the investigational drug, was reportedwithin 24 h by telephone or facsimile. Appropriate authorities were tobe informed if the serious or unexpected adverse experience, in theopinion of inventors, was likely to affect the safety of other patientsor volunteers or the conduct of the trial.

[0166] 7. Clinical Supplies-Study Medication

[0167] Formulation: Unit 3 g GHB doses (Lot PK1) were obtained fromOrphan Medical. Each unit dose comprised twin foil pouches: one pouchcontaining GHB and the other containing a flavor excipient blend. (Table8 formulation)

[0168] Labeling: The clinical supplies for individual patients werepackaged in separate containers. Each container included two unit doses,i.e. two twin-pouches. Clinical supplies for eight patients (includingthose for two replacement patients) were delivered to the investigator.Foil twin-pouches were identified with a two-part label.

[0169] Dose Administration: The investigator or designee prepared theoral solution for dosing within 30 min prior to the first oraladministration to individual patients. The contents of one twin-pouchwas emptied into a dosing cup to which two ounces of water were added.After replacing the lid of the dosing cup, it was gently shaken todissolve the GHB and excipient in water. The GHB solution was ingestedin its entirety. Likewise, the second GHB dosing solution was preparedin the same manner and was ingesting in its entirety at 4 h after thefirst GHB dose.

[0170] Investigational Drug Accountability: At the conclusion of thestudy, all clinical supplies were accounted for on the drugaccountability form and unused drug supplies were returned for properdisposition.

[0171] 8. Determination of Plasma GHB Concentrations

[0172] Plasma samples were analyzed for GHB by the Department ofBioanalytical Chemistry (Covance (previously known as Hazelton Corning),Madison, Wis.) A gas chromatographic method with mass selectivedetection (GC-MSD) was used in the analysis.

[0173] 9. Data Management and Analysis

[0174] Data Base: An EXCEL data base (spreadsheet) was constricted fromdata recorded on Case Report Forms (CFR) and plasma GHB concentrationdata sets received from Covance (Corning Hazleton). Each entry in theEXCEL spreadsheet was checked against the CRFs and any data entry errorfound was corrected.

[0175] Pharmacokinetic Analysis: Pharmacokinetic parameters weredetermined for individual sets of plasma GHB concentration vs. time datausing the non-compartmental routine in WinNonlin Version 1.1. The peakGHB concentrations (C_(max)) and the times of their respectivelyoccurrences (t_(max)) were observed values. Terminal half-life (T_(1/2))was obtained by log-linear regression analysis of the terminal phase ofconcentration vs. time curves. The area under the curve (AUC_(inf)) andthe area under the first moment curve (AUMC_(inf)) were calculated bythe linear trapezoidal rule up to the last determined concentration andincluded extrapolated areas to time infinity. Apparent oral clearance(CL/F) was calculated as Dose/AUC_(inf). Volume of distribution (Vz/F)was determined by taking the ratio between CL/F and λ_(z) (eliminationrate constant). Mean residence time (MRT) was estimated from the ratiobetween AUMC_(inf) and AUC_(inf).

[0176] Safety Analyses: Results of physical examinations, vital signs,clinical laboratory data were summarized in tabular form and presentedby patient number. Adverse events also were tabulated in a similarfashion.

[0177] 10. Results

[0178] Patient and Study Accountability: Six narcoleptic patients wereenrolled and all six completed the study in its entirety.

[0179] Protocol Compliance: There were no inclusion criteria violations.All patients admitted into the study met the study entrance requirementsand completed the screening phase at least one day before the treatmentphase.

[0180] All six patients took non-study medications in addition tomethylphenidate and GHB doses because none of their concomitantmedications (Synthyroid, Premarin, Lovastatin, Flovastatin, furosemide,potassium, hydrochlorothiazide, lansoprazole, and verapamil) were on theexclusion list (which included hypnotics, sedatives, antidepressants,antihistamines, clonidine, and anticonvulsants). Adverse experienceprobes, vital sign measurements, and essentially all pharmacokineticblood samples were performed at protocol specified times; the fewdeviations in blood sampling times should not have any impact on theoutcome of the study since actual blood sampling times were used in thepharmacokinetic analysis.

[0181] The diagnosis of narcolepsy for at least one year in each patientwas verified by a nocturnal polysomnogram (NSG) and a Multiple SleepLatency Test (MSLT) conducted at a qualified laboratory. Five patientshave been maintained on GHB nightly for over 10 years and one patienthas been receiving GHB nightly for two years. One patient (Subject 101)also had multiple sclerosis; however, the attending physician, judgedthat it would not interfere with the objective of this study. A few ofthe screening clinical laboratory results marginally fell outside thereference range but none was considered by the attending physician to beclinically significant.

[0182] Exposure to Study Drug: All patients ingested the two GHB dosesas scheduled (immediately prior to bedtime). The GHB doses per kg bodyweight ranged from 26.4 to 52.4 mg/kg.

[0183] Plasma GHB Concentration Profiles: It was noted that, in certaincases, (Patients #103, and #106), plasma GHB concentrations did notdecline from the first C_(max) to zero concentration at h 4. Uponachievement of the second C_(max), the semi-logarithmic plots ofconcentration versus time data in Patients #102, #103, and #105exhibited a convex decline profile. Such a decline pattern suggestednon-linear pharmacokinetics. The highest plasma GHB concentrationobserved in the study was 125.0 μg/mL which occurred in Subject 101after the second 3 g GHB dose.

[0184] Pharmacokinetic Parameter Estimates: The mean (±SD) showed thatmaximum GHB concentrations (C_(max)) were 62.8±27.4 μg/mL and 91.2±25.6μg/mL for the first and second GHB doses, respectively. Thecorresponding mean observed times to maximum concentrations were 40±6and 36±7 min after the first and second GHB doses, respectively. Themean AUC_(inf) was 17732±4603 μg/mL.h. The mean CL/F was 4.2±1 mL/min/kgand the mean V_(z)F was 307±96 mL/kg. The mean MRT_(inf) was 249±56 min.The mean GHB T_(1/2), estimated by linear regression of log[C] vs. timedata of the terminal phase of the second GHB dose was 53±19 min.

[0185] Adverse Experiences: No adverse experiences were reported in thestudy.

[0186] Follow-up Safety Assessments: Inspection of screen and follow-upphysical examination results per individual patient did not identify anychanges attributable to GHB.

[0187] 11. Discussion

[0188] To the inventors' knowledge, the level of GHB in human systemiccirculation has not been reported in the literature. Hence, baseline (0h) plasma samples were analyzed for GHB concentrations. The GC-MSDmethod used in the present study had a limit of quantification (LOQ) of7.02 μg/mL and analysis of the baseline plasma samples showed theendogenous levels of GHB are below this sensitivity limit. This findingwas confirmed by adding known amounts of GHB (5, 10, and 25 μg per mL ofplasma) to blank human plasma samples and subjected these samples toGC-MSD analysis. This method of standard addition allowed an estimationof the endogenous GH1B level in human plasma which was found to averageabout 2.02 μg/mL, (i.e. approximately {fraction (2/7)} of the Limit OfQuantitation (LOQ) for a validated assay. Hence, the endogenous GHBlevel was not subtracted from exogenous GHB concentrations prior topharmacokinetic analysis.

[0189] Values of mean t_(max) (˜40 min after dosing) and t_(1/2) (˜35min) suggest that the GHB solution administered to narcoleptic patientsin this study was readily absorbed and rapidly eliminated. In 3 out of 6patients the drug was essentially gone from the systemic circulation byh 4 after the first GHB dose whereas in the remaining three patientsresidual GHB levels of ˜15 μg/mL was still detected at h 4.

[0190] The convex nature of the decline of plasma GHB concentrations inthree patients after achievement of the second C_(max) indicated thatelimination of GHB from the systemic circulation in these three patientsis capacity limited. Nevertheless, it should be noted that plasma GHBconcentrations were no longer detectable by h 6 after the second GHBdose (10 h after the first GHB dose). The mean apparent oral clearancefound in this study was 4.2±1.0 mL/min/kg and appeared to be comparableto the apparent oral clearance of 5.3±2.2 mL/min/kg reported in theliterature for a group of alcohol dependent patients who wereadministered a dose of 50 mg/kg (Ferrara, 1992). While it appeared thatthe GHB dose (ranging from 26.4 to 52.4 mg/kg with a mean of 36.5 mg/kg)in the present study was lower than the comparison GHB dose (50 mg/kg)administered to the alcohol dependent patients (Ferrara, 1992), itshould be noted that each patient in the present study was administeredtwo consecutive GHB doses at four-hour interval and residual GHB levelswere detected in three out of six patients immediately prior to thesecond GHB dose. The GHB pharmacokinetic non-linearity in alcoholdependent patients easily can be observed from the apparent oralclearance which increased to 8.1±4.8 mL/min/kg when the GHB dose isreduced to 25 mg/kg dose (Ferrara, 1992). In the present study, thenon-linearity was less obvious because each narcoleptic patient receivedtwo consecutive fixed 3 g doses regardless of body weight.

[0191] The mean elimination half-life of GHB in the six narcolepticpatients was determined to be 53±19 min, longer than that in alcoholdependent patients after a 50 mg/kg GHB dose (Ferrara, 1992). Thelengthening of GHB elimination half-life observed in this studypartially was caused by the wider spacing in sampling time points.However, capacity limited elimination of this drug in some of thenarcoleptic patients also could have contributed to this prolongation.

[0192] GHB appears to have a shortcoming in that its elimination fromthe body is capacity limited in some patients when the drug isadministered at a fixed regimen of 3 g twice nightly at four-hourinterval. However, from a therapeutic perspective, GHB offers anadvantage in the treatment of narcolepsy because by the time a patientwakes up in the morning (i.e. 8 to 10 h after the first GHB dose), allGHB, including that from the second dose, will have been eliminated fromthe systemic circulation. GHB was also well tolerated by narcolepticpatients in this study. No adverse experience was reported.

[0193] 12. Conclusions

[0194] The capacity limited elimination kinetics was observed in threeout of six patients who had been administered two consecutive 3 g oraldoses of GHB, 4 h apart. From a pharmacokinetic perspective, dividingthe nightly GHB dose into two portions and administering the twoportions to narcoleptic patients at a 2.5- to 4-h interval was rationalbecause the elimination half-life of GHB was short (<1 h). Thepharmacokinetic profiles of GHB in narcoleptic patients who had beenreceiving this agent nightly for years appeared to be comparable tothose in alcohol dependent patients (Ferrara, 1992).

EXAMPLE 4 Sodium Oxybate Formulation Study

[0195] I. Study Objectives

[0196] This example described ways that sodium oxybate may be preparedand tested for stability to determine preferred formulations. Variousformulations of sodium oxybate in water were prepared under differentconditions of mixing and with addition of selected acidulents atmultiple pH levels (Neo-Pharm Laboratories, Blainville, Quebec).Selected formulations were placed on real time and acceleratedstability. Earlier studies have demonstrated that degradation productsare formed in acidic conditions and that antimicrobial effectiveness islimited at high pH. Therefore several acidulents across a range of6.0-9.0 were evaluated.

[0197] II. Study Design-Part I

[0198] The following experimental work is designed to be performed intwo stages. Initial studies were conducted to evaluate the impact ofconditions of formulation, pH and acidulent on the resultant levels ofimpurities, specified and unspecified, and potency of sodium oxybate.Sodium oxybate was prepared (MDS Neo-Pharm Laboratories, Quebec Canada),under different conditions of mixing and with addition of selectedacidulents at multiple pH levels. These formulations of sodium oxybateacidulent were then tested.

[0199] A. Preliminary Studies

[0200] 1. Formulations Description

[0201] All formulations were prepared at a concentration of 500 mg/cc ofsodium oxybate in water. Three acidulents (HCl, malic acid, andphosphoric acid), were selected and tested at pH 6.0, 7.5 and 9.0.

[0202] 2. Method of Formulation

[0203] Solutions, were prepared using the described methods:

[0204] a. Rapid Mix Method

[0205] Sodium oxybate was dissolved in water and concentrated acidulentwas added immediately without temperature control. Temperature ofsolution was monitored and recorded prior to and during addition ofacidulent. The time of equiliberation to room temperature was alsorecorded. After the solution reached ambient room temperature, it wasfiltered through a 10 μm filter.

[0206] b. Cool Mix Method:

[0207] Sodium oxybate was dissolved in water. Acidulent was diluted to10% and slowly added. The solution was cooled by water with jacket orice bath. Monitor and record the temperature of the solution wasmonitored and recorded during addition of acidulent. The time ofequilibrium from room temperature was also recorded. The preferredmaximum temperature should be maintained at less than 40° C. Thesolution was filtered through a 10 μm filter.

[0208] C. Reverse Order of Addition:

[0209] Acidulent was added to water and cooled to room temperature. Thesodium oxybate was dissolved in the diluted acidulent solution. Thetemperature of solution was monitored and recorded during addition ofsodium oxybate. The solution was filtered through a 10 μm filter.

[0210] d. Sodium Oxybate Control

[0211] Sodium oxybate was dissolved in water to a concentration of 500mg/cc with no added acidulent. The final pH was recorded and thesolution was filtered through a 10 μm (micron or micrometer) filter.

[0212] 3. Solution Data:

[0213] Data was recorded for each solution which included: 1) date ofpreparation 2) date of analysis, 3) amount of acidulent required toachieve target pH, 4) length of time for dissolution of sodium oxybate,5) temperature profile of solution over time of solution preparation tobe recorded at 15 minute intervals, 6) final pH of solution.

[0214] 4. Testing Requirements:

[0215] The following methods were used to test the prepared solutions:pH, HPLC (High Pressure Liquid Chromotography) for potency (sodiumoxybate), and for impurities. Time 0 analysis was performed immediately(within 24 h). RRT=(relative retention time).

[0216] B. Summary of Part I:

[0217] 1. Preliminary Evaluation of Sodium Oxybate Formulations

[0218] Tables 13, 14 and 15 provide test results for the three methodsof preparation of sodium oxybate formulations. TABLE 13 FormulationStudy/PR98068 Results of Formulation Study - Time Zero determinations ofSodium Oxybate, GBL and Unspecified Impurities Preparation Method AAddition of Concentrated Sodium Acidulent* Oxybate Impurities Impurities(Amount of Acidulent in 1000 ml) mg/cc Specified Unspecified Date ofPreparation/Date of Assay Target pH % % GBL % [Specification] [Target ±0.5] Final pH [95-105%] [≦0.5%] [≦0.1% Total] HCl (Apr. 23, 1998) pH 9.09.0 509 mg/cc 0.009% RRT 4.88 = 0.01% (10 drops over 2 minutes) 101%(2.5 ml/4 minutes) pH 7.5 7.5 507 mg/cc  0.01% RRT 4.89 = 0.02% 101% (45ml/34 minutes) pH 6.0 6.0 504 mg/cc 0.033% RRT 4.89 = 0.33% 101% MalicAcid (Apr. 24, 1998) pH 9.0 9.1 498 mg/cc 0.009% RRT 4.89 = 0.01% (0.12gm) 99.6%  (1.6 gm) pH 7.5 7.6 506 mg/cc 0.009% RRT 4.89 = 0.01% 101%(25 gm) pH 6.0 6.2 493 mg/cc 0.011% RRT 4.89 = 0.01% 98.6%  H₃PO₄ (Apr.24, 1998) pH 9.0 9.0 493 mg/cc 0.009% RRT 4.89 = 0.01% (2 drops) 98.6% (1.0 ml) pH 7.5 7.5 493 mg/cc 0.009% RRT 4.89 = 0.02% 98.6%  (17.3 ml)pH 6.0 6.1 497 mg/cc 0.063% RRT 4.89 = 0.02% 99.4%  Sodium OxybateControl n.a. 9.8 500 mg/cc 0.009% RRT 4.89 = 0.04% No Acidulent 100%

[0219] TABLE 14 Preparation Method B Addition of Diluted Acidulent*Sodium Impurities Impurities (Amount of Acidulent in 1000 ml) OxybateSpecified Unspecified Date of Preparation/Date of Assay Target pH mg/ml% % GBL % [Specification] [Target ± 0.5] Final pH [95-105%] [≦0.5%][≦0.1% Total] HCl (25%) (Apr. 28, 1998) pH 9.0 9.1 500 mg/cc 0.009% RRT4.88 = 0.01% (20 drops) 100% (8.0 ml) pH 7.5 7.6 499 mg/cc 0.009% RRT4.88 = 0.01% 99.8%  (175 ml) pH 6.0 6.0 502 mg/cc 0.016% RRT 4.88 =0.02% 101% H₃PO₄ (25%) (Apr. 29, 1998) pH 9.0 8.9 499 mg/cc 0.007% RRT4.92 = 0.02% (0.3 ml) 99.8%  (4.0 ml) pH 7.5 7.5 497 mg/cc 0.008% RRT4.89 = 0.02% 99.4%  (120 ml) pH 6.0 6.0 499 mg/cc 0.019% RRT 4.89 =0.01% 99.8%  Malic Acid (500 mg/cc) (Apr. 30, 1998) pH 9.0 9.0 495 mg/cc0.008% RRT 4.92 = 0.02% (0.115 gm/0.23 ml)  99% (1.75 gm/3.5 ml) pH 7.57.4 488 mg/cc 0.009% RRT 4.92 = 0.01% 97.5%  (35 gm/70 ml) pH 6.0 6.0487 mg/cc 0.013% RRT 4.92 = 0.01% 97.0% 

[0220] TABLE 15 Preparation Method C Sodium Reverse Order of Addition*Oxybate Impurities Impurities (Amount of Acidulent in 1000 ml) mg/mlSpecified Unspecified Date of Preparation/Date of Assay Target pH % %GBL % [Specification] [Target ± 0.5] Final pH [95-105%] [≦0.5%] [≦0.1%Total] HCl (May 1, 1998) pH 9.0 9.0 497 mg/cc 0.006% RRT 4.92 = 0.03%(20 drops) 99.4%  (2.4 ml) pH 7.5 7.6 504 mg/cc 0.004% RRT 4.92 = 0.04%101% (45 ml) pH 6.0 6.0 493 mg/cc 0.044% RRT 4.92 = 0.04% 98.6%  H₃PO₄(May 4, 1998) pH 9.0 8.9 496 mg/cc 0.005% RRT 4.91 = 0.03% (0.08 ml)99.2%  (1.0 ml) pH 7.5 7.6 496 mg/cc 0.004% RRT 4.91 = 0.04% 99.2%  (30ml) pH 6.0 6.1 489 mg/cc 0.023% RRT 4.91 = 0.04% 97.8%  Malic Acid (May5, 1998) pH 9.0 9.0 495 mg/cc 0.006% RRT 4.93 = 0.02% (0.12 gm)  99%(1.6 gm) pH 7.5 7.6 497 mg/cc 0.004% RRT 4.93 = 0.04% 99.4%  (35 gm) pH6.0 6.2 495 mg/cc 0.044% RRT 4.93 = 0.04%  99%

[0221] Review of the data indicated that the optimum method forpreparation of sodium oxybate with minimal impurity levels is Method B:Controlled mixing with diluted acidulent. Method 2b resulted informulations with lowest levels of GBL.

[0222] 2. Conclusions.

[0223] Additional evaluations were carried out on selectedformulations: 1) sodium oxybate with HCl as acidulent, at pH 7.5, and 2)sodium oxybate with malic acid as acidulent, pH 6.0, 7.5, and 9.0.

[0224] III. Study Design-Part II

[0225] Microbial Challenge and Stability Tested to determine the mostpreferred embodiments, the number of formulations was limited to threebased on the data prepared from the above experiments.

[0226] A. Kinetic Stability Study with Selected Formulations

[0227] Samples of formulations are stored in tightly closed containers.Storage Conditions were 25° C., 40° C., and 60° C. Time points inbrackets were tested at the inventor's discretion. The samples weretested according to the following schedule: at 25° C. storagetemperature, the assay points will be 0, 14, 28, 45, 60 days and 120days; at 40° C. storage temperature, the assay points will be 0, 7, 14,28, 45, 60 days; at 60° C. storage temperature, the assay points will beat 0, 3, 7, 14, 28, 45 days, and, 60 days.

[0228] The testing requirements included pH, HPLC for sodium oxybate(duplicate injections of single sample preparation), and impurities,specified and unspecified.

[0229] B. Preservative Effectiveness Testing of Selected Formulations

[0230] Microbial challenge testing of formulations was preformedaccording to USP XXIII, <51>, Eighth Supplement. Solutions aredetermined to “Pass or Fail” based upon the USP criteria forperservative effectivness which states: For Bacteria, “Not less than 1log reduction from the initial microbial count at 14 days and noincrease from the 14 days count at 28 days;” and for yeast and molds,“No increase from the initial calculated count at 14 and 28 days.”Solutions which met these criteria were designated as “Pass” and thosethat did not meet these criteria were designated as “Fail”.

[0231] C. Summary Stability Results:

[0232] 1. Formulations Prepared with Malic Acid as Acidulents:

[0233] a. Malic Acid, pH 6.0 formulation (250), GBL and impurity Alevels were very low on Day 0, however, by Day 45 GBL levels had reached2.8%. Impurity A increased from 0.01 to 1.0%, and pH increased from 6.0to 6.3 by day 45. This formulation stored at 40° C. and 60° C. showedGBL levels up to 5.4%, impurity A levels increased to 2.3%, and pHincreased to 6.3 by Day 14.

[0234] b. Malic Acid, pH 7.5 formulation (25° C. ), GBL levels were0.009% on Day 0, and increased to 0.17% by day 45. Impurity A increasedfrom 0.01% to 0.1% and pH increased from 7.5 to 7.9. Malic acid, pH 7.5GBL levels are reached (40° C.) and 60° C. a maximum of 0.22%. ImpurityA levels reached 0.1% and pH increased to 8.0. Under acceleratedconditions, all parameters reached an apparent maximum by Day 7 and didnot increase significantly thereafter.

[0235] C. Malic Acid, pH 9.0 formulation (25° C.,) GBL levels measure0.008% on Day 0, and increased slightly to 0.013% on Day 45. Impurity Adid not increase nor did pH increase. Under accelerated conditions, GBLincreased from 0.008% to a maximum of 0.018% by Day 14. Impurity Aincreased slightly from 0.10 to 0.014% by Day 14.

[0236] 2. Formulations Prepared with HCl as Acidulents.

[0237] HCl, pH 6.0 formulation (25°) GBL levels measured 2.8% by Day 30,and impurity A 0.004%, and pH 6.0. Accelerated storage conditions (40°C.) GBL levels were measured at 6.6%, and impurity A measured 3.1% byDay 30.

[0238] HCl, pH 7.5 formulation (25%) GBL levels measured 0 041% on Day0, Impurity A measured 0.02%, and by Day 18 GBL measured to 0.12% andimpurity A to 0.07%. Under accelerated conditions (40° C. and 60° C.),GBL increased to a maximum of 0.21%, impurity A increased from 0.02% to0.1%, and pH increased from 7.5 to 8.0. As with Malic Acid at pH 7.5,the measured parameters reached maximum by Day 7 and did not increasesignificantly thereafter.

[0239] HCl, pH 9.0 formulation (25° C.) GBL levels reached 0.022% by Day18. Impurity A stayed constant at 0.01% for 18 days. Under acceleratedconditions (40° C.) GBL levels were equivalent to 25° C. storage(0.21%). Impurity A showed no increase over 25° C. conditions.

[0240] 3. Conclusions.

[0241] Formulations selected for microbial challenge testing were thefollowing: HCl, pH 7.5, and malic acid, pH 7.5. The rationale for thisdecision was twofold. First, the formulations were selected based onminimal formation of GBL and impurity A. Second, the formulations wereselected to maintain a pH in the neutral range.

EXAMPLE 5 Further Evaluation of Sodium Oxybate Formulations

[0242] Purpose: To prepare, test and evaluate multiple formulations ofSodium Oxybate and two formulations using alternative salts ofgamma-hydroxybutyrate.

[0243] Scope: Various formulations of Sodium Oxybate in water wereprepared with addition of selected acidulents at multiple pH levels.Solutions were prepared and tested at Neo-Pharm Laboratories,Blainville, Quebec. All formulations successfully prepared were placedon limited stability. Earlier studies have demonstrated that degradationproducts are formed in acidic conditions and that antimicrobialeffectiveness is limited at high pH. Conditions of varying pH andconcentrations of sodium oxybate previously not evaluated were preparedand tested.

[0244] Procedures: Solutions were prepared as summarized and microbialchallenge testing carried out as follows:

[0245] I. Evaluation of Sodium Oxybate Formulations

[0246] Purpose: To prepare, test and evaluate multiple formulations ofSodium Oxybate and two formulations using alternative salts ofgamma-hydroxybutyrate.

[0247] Scope: Various formulations of Sodium Oxybate in water wereprepared with addition of selected acidulents at multiple pH levels.Selected formulations were studied for limited stability. Earlierstudies demonstrated that degradation products are formed in acidicconditions and that antimicrobial effectiveness is limited at high pH.Conditions of varying pH and concentrations of sodium oxybate previouslynot evaluated were prepared and tested.

[0248] Responsibility: It was the responsibility of Neo-PharmLaboratories to prepare selected formulations and perform testing perthis protocol. Orphan Medical, New Medicine Development and QualityAssurance were responsible for reviewing raw data at the defineddecision point, defining which formulations will be included instability testing. Orphan Medical was also responsible for reviewingfinal results (raw data) and the final report.

[0249] Procedure: The following formulations were prepared by scientistsat Neo-Pharm following the steps listed below and dispensed intocontainers (amber PET 240 ml bottle, OMI CS-460) and closures (Clic-LocIII, 24-400, OMI CS-470) to a volume of 200 ml each bottle. The bottleswere tested by 28-day microbial challenge and by limited stabilitytesting at 25° C. including, appearance, pH, potency, and impurityprofile on day 1 (day of preparation) and day 28.

[0250] A. Formulations Prepared and Evaluated Using Sodium Oxybate:TABLE 16 Formulations Prepared and Evaluated Using Sodium OxybateFormulation Sodium Oxybate ID No. Concentration Acidulent Final pH 1 500mg/cc Malic Acid 7.5 2 250 mg/cc Malic Acid 7.5 3 350 mg/cc Malic Acid7.5 4 450 mg/cc Malic Acid 7.5 5 550 mg/cc Malic Acid 7.5 6 650 mg/ccMalic Acid 7.5 7 500 mg/cc Citric Acid 7.5 8 500 mg/cc Malic Acid 5.0

[0251] 1. Preparation: Method for preparation of various formulations:As previously determined in PR98068, the method of choice forpreparation of liquid formulations of sodium oxybate was the following:

[0252] a. For a one liter quantity of product, add the sodium oxybate in500 ml of purified and stir until dissolved. Prepare a 10% solution ofthe acid (Malic or Citric) and add slowly to the solution of sodiumoxybate. The solution should be monitored for pH and temperature andboth variables recorded at reasonable intervals (every 10 or 15minutes). When the target pH is attained, the solution will be Q. S. to1 liter, and pH rechecked and recorded.

[0253] b. The final solutions will be filtered through 10 μm filters and200 mL dispensed into 5 amber PET bottles with closures (provied byOrphan Medical, Inc.). Two bottles will be used for microbial challengestudies and the remaining three bottles will be placed on limitedstability.

[0254] 2. Testing: Formulations were tested by two methods ofevaluation:

[0255] a. Limited stability evaluation:

[0256] (1) Storage Conditions: 25° C.

[0257] (2) Pull Points: Day 0 (day of preparation), and day 28

[0258] (3) Testing Requirements: Test Method Appearance Visual PotencyHPLC Neopharm 764 Impurities HPLC Neopharm 793DT pH USP <791>

[0259] b. Microbial challenge:

[0260] (1) Storage Conditions: Microbial challenge studies of aboveformulations were set up with 5 microorganisms and stored for 28 days at20-25° C., per USP <51> Eighth Supplement.

[0261] (2) Microorganisms: After a sufficient quantity of eachformulation is prepared, aliquots were inoculated with 5 microorganismsat a concentration of at least 10⁵ microorganisms/cc: (a) Escherichiacoli, ATCC 8739 (b) Pseudomonas aeruginosa, ATCC 9027 (c) Staphylococcusaureus, ATCC 6538 (d) Aspergillus niger, ATCC 18404 (e) Candidaalbicans, ATCC 10231

[0262] (3) Time Points: A determination of the viable cell concentrationin each inoculated container was performed after 0, 1, 3, 7, 14, 21 and28 days.

[0263] B. Formulations To Be Prepared From Alternative Salts ofGamma-Hydroxybutyrate: This work may be staged to take place at a latertime than the work described above. TABLE 17 Formulation DetailFormulation Concentration ID No. Salt of GHB of Salt of GHB AcidultentFinal pH 9 Calcium salt 500 mg/cc Malic Acid 7.5 (Or maximum (Ifcompatible) possible*)

[0264] 1. Solubility determination: Little information is availableabout the solubility of this alternative salt of gamma-hydroxybutyrateand a determination of solubility was done in advance of efforts toprepare formulations for evaluation by stability and microbialchallenge. Maximum solubility is evaluated for pH unadjusted soluationsand within the pH range desired for this formulation (pH 6.0-8.0). Ifsolubility is limited, the formulation will be changed to accommodatethe solubility limitations. The preferred acidulent for this work isMalic acid. If acid is not compatible with the salt, then an alternativeacid can be selected.

[0265] 2. Preparation: Method for preparation of alternative saltformulations:

[0266] a. The previously described method (Part A) is used forpreparation of formulations of calcium gamma-hydroxybutyrate at theconcentrations and specified pH determined by solubility experiments.

[0267] b. The final solutions were filtered through 10μm filters anddispensed into 5 amber PET bottles with closures (provided by OrphanMedical, Inc.). Two bottles are used for microbial challenge studies andtwo bottles are placed on limited stability. The remaining bottles areretained for any additional studies at a future time.

[0268] 3. Testing: Formulations are tested as described above.

[0269] C. Reporting of Results: The results will be reported for theStability and Microbial Challenge results in standard format as definedby the described Orphan Medical Development. Copies of HPLCchromatograms and any raw data from these studies will be provided withresults.

[0270] D. Acceptance Criteria: Specific acceptance criteria for thisstudy can be described analogous to those for sodium oxybate.

[0271] Results: Summarized as follows in Tables 18, 19 and 20 forvarious studies. TABLE 18 Result Summary Results of Protocol 98126Microbial Challenge Study 0 Day 1 Day 7 Day 14 Day 21 Day 28 Lot NumberMCH1064-33 GHB, pH 7.50, 500 mg/cc Malic Acid E. coli 490,000 5,500 <100<10 <10 <10 P. aeruginosa 141,000 21,600 <100 <10 <10 <10 S. aureus1,035,000 405,000 79,500 8,300 1,645 375 C. albicans 835,000 147,000<100 <10 <10 <10 A. niger 370,000 285,000 120,500 246,500 148,500183,000 Lot Number MCH1064-35 GHB, pH 7.50, 250 mg/cc Malic Acid E. coli705,000 229,500 <100 <10 <10 <10 P. aeruginosa 224,500 5,200 <100 <10<10 <10 S. aureus 1,135,000 390,000 262,500 31,500 4,250 155 C. albicans705,000 435,000 52,000 850 <10 <10 A. niger 510,000 515,000 155,500176,000 147,500 184,000 Lot Number MCH1064-37 GHB, pH 7.50, 350 mg/ccMalic Acid E. coli 365,000 310,000 13,400 <10 <10 <10 P. aeruginosa205,000 15,600 50 <10 <10 <10 S. aureus 1,170,500 605,000 67,500 <60 60<10 C. albicans 870,000 355,000 8,300 <10 <10 <10 A. niger 540,000525,000 172,000 155,500 155,500 163,500 Lot Number MCH1064-43 GHB, pH7.50, 550 mg/cc Malic Acid E. coli 425,000 63,500 700 <10 <10 <10 P.aeruginosa 171,500 211,550 250 <10 <10 <10 S. aureus 1,020,000 520,00041,500 1,050 180 10 C. albicans 880,000 157,500 800 <10 <10 <10 A. niger545,000 505,000 131,000 156,500 205,000 187,500 Lot Number MCH1064-45GHB, pH 7.50, 550 mg/cc Malic Acid E. coli 660,000 58,500 450 <10 <10<10 P. aeruginosa 896,000 14,450 900 <10 <10 <10 S. aureus 860,000132,000 19,750 935 110 45 C. albicans 1,125,000 166,000 <100 <10 <10 <10A. niger 530,000 530,000 105,500 153,000 157,500 177,000 Lot NumberMCH1046-47 GHB, pH 7.50, 650 mg/cc Malic Acid E. coli 630,000 119,0001,350 <10 <10 <10 P. aeruginosa 183,500 5,900 50 <10 <10 <10 S. aureus890,000 650,000 76,000 14,550 510 1,150 C. albicans 675,000 145,500 <100<10 <10 <10 A. niger 535,000 385,000 103,000 162,000 187,000 173,000 LotNumber MCH1064-85 Ca-Oxybate, pH 7.50, 500 mg/cc Malic Acid E. coli425,000 121,000 1,650 <10 <10 <10 P. aeruginosa 420,000 22,000 300 <10<10 <10 S. aureus 265,000 2,000 <100 <10 <10 <10 C. albicans 565,000440,000 29,500 <1000 <10 <10 A. niger 1,310,000 965,000 370,000 640,000690,000 675,000 Lot Number MCH1064-49 GHB, pH 7.50, 500 mg/cc CitricAcid E. coli 615,000 6,500 <100 <10 <10 <10 P. aeruginosa 69,500 14,600<100 <10 <10 <10 S. aereus 650,000 305,000 1,700 <10 <10 <10 C. albicans720,000 107,000 <100 <10 <10 <10 A. niger 375,000 380,000 99,500 178,500212,500 165,500

[0272] TABLE 19 Result Summary Data from Dec. 30, 1997 (n = 3) Inoculu 0Day 1 Day 3 Day 7 Day 14 Day 21 Day 28 Results GHB (pH 7.5) 750 mg/cc E.coli 470,000 160,000 64,500 4,300 420 <10 <10 <10 P. aeruginos 437,500152,000 3,500 10 <10 <10 <10 <10 S. aureus 447,500 330,000 24,500 42,0008,050 1,935 15 10 C. albicans 375,000 234,500 28,000 1,950 <10 <10 10<10 A. niger 475,500 395,000 395,000 229,000 101,500 161,500 101,000202,000 750 mg/cc + 0.2% MP/PP, pH 7.50 E. coli 470,000 127,000 <1,000<10 <10 <10 <10 <10 P. aeruginos 437,500 61,000 <1,000 <10 <10 <10 <10<10 S. aureus 447,500 350,000 3,000 4,050 <10 <10 <10 <10 C. albicans375,000 103,500 <1,000 <10 <10 <10 <10 <10 A. niger 457,500 315,000415,000 35,500 79,500 38,500 87,500 6,400 750 mg/cc + 0.1% MP/PP, pH 7.5E. coli 470,000 157,000 7,000 <10 <10 <10 <10 <10 P. aeruginos 437,50090,000 <1,000 <10 <10 <10 <10 <10 S. aureus 447,500 239,000 5,500 16,950600 <10 <10 <10 C. albicans 375,000 169,000 <1,000 <100 <10 <10 <10 <10A. niger 457,500 335,000 425,000 34,500 168,500 90,500 95,500 99,000 750mg/cc + 0.2% Potassium sorbate, pH 7.5 E. coli 470,000 180,000 735,0006,200 475 <10 <10 <10 P. aeruginos 437,500 152,000 1,000 <10 <10 <10 <10<10 S. aureus 447,500 264,000 27,500 49,800 14,550 2,370 <10 <10 C.albicans 375,000 300,000 41,500 3,800 <10 <10 <10 <100 A. niger 457,500325,000 360,000 25,000 202,000 500,000 345,000 425,000 GHB (pH 6.0) 500mg/cc E. coli 470,000 221,000 40,000 100 <10 <10 <10 <10 P. aeruginosa437,500 172,000 3,000 <10 <10 <10 <10 <10 S. aureus 447,500 320,000<1,000 30 <10 <10 <10 <10 C. albicans 375,000 310,000 14,000 100 <10 <10<10 <10 A. niger 475,500 270,000 355,000 84,000 120,000 48,500 41,0008,600 PASS 500 mg/cc + 0.2% MP/PP, pH 6.0 E. coli 470,000 163,000 <1,000<10 <10 <10 <10 <10 P. aeruginosa 437,500 60,000 <1,000 <10 <10 <10 <10<10 S. aureus 447,500 243,000 <1,000 <10 <10 <10 <10 <10 C. albicans375,000 150,500 <1,000 <100 <10 <10 <10 <10 A. niger 475,500 400,00038,000 <10 <10 <10 <10 <10 PASS 500 mg/cc + 0.1% MP/PP, pH 6.0 E. coli470,000 206,000 <1,000 <10 <10 <10 <10 <10 P. aeruginosa 437,500 118,000<1,000 <10 <10 <10 <10 <10 S. aureus 447,500 330,000 <1,000 <10 <10 <10<10 <10 C. albicans 375,000 221,000 <1,000 <100 <10 <10 <10 <10 A. niger475,500 355,000 93,500 59,000 8,700 315 35 <10 PASS 500 mg/cc + 0.2%Potassium sorbate, pH 6.0 E. coli 470,000 222,000 46,500 150 <10 <10 <10<10 P. aeruginosa 437,500 136,000 <1,000 <10 <10 <10 <10 <10 S. aureus447,500 410,000 <1,000 130 <10 <10 <10 <10 C. albicans 375,000 395,00028,500 <100 <10 <10 <10 <10 A. niger 475,500 405,000 270,000 63,00051,000 49,500 39,000 11,150 PASS

[0273] TABLE 20 Result Summary Inoculum 0 Day 1 Day 3 Day 7 Day 14 Day21 Day 28 Data from Study Dated Dec. 30, 1997 GHB (pH 6.0) 500 mg/cc E.coli 470,000 221,000 40,000 100 <10 <10 <10 <10 P. aeruginosa 437,500172,000 3,000 <10 <10 <10 <10 <10 S. aureus 447,500 320,000 <1,000 30<10 <10 <10 <10 C. albicans 375,000 310,000 14,000 100 <10 <10 <10 <10A. niger 475,500 270,000 355,000 84,000 120,000 48,500 41,000 8,600 DataFrom Study Begun Mar. 12, 1998 GHB (pH 6.0) 500 mg/cc E. coli 500,000370,000 nd nd <100 <10 <10 <10 P. aeruginosa 350,000 198,500 nd nd <100<10 <10 <10 S. aureus 280,000 480,000 nd nd <100 <10 <10 <10 C. albicans450,000 340,000 nd nd <100 <10 <10 <10 A. niger 450,000 445,000 nd nd9,050 20,500 9,450 1,120 GHB (pH 6.0) 500 mg/cc E. coli 500,000 199,000nd nd <100 <10 <10 <10 P. aeruginosa 350,000 192,500 nd nd <100 <10 <10<10 S. aureus 280,000 300,000 nd nd <100 <10 <10 <10 C. albicans 450,000370,000 nd nd <100 <10 <10 <10 A. niger 450,000 445,000 nd nd 10,10022,750 3,800 4,050 GHB (pH 9.0) 500 mg/cc E. coli 500,000 320,000 nd nd<100 <10 <10 <10 P. aeruginosa 350,000 12,000 nd nd <100 <10 <10 <10 S.aureus 280,000 530,000 nd nd <100 <10 <10 <10 C. albicans 450,000510,000 nd nd <100 <10 <10 <10 A. niger 450,000 345,000 nd nd 13,800158,500 315,000 110,500 GHB (pH 9.0) 500 mg/cc E. coli 500,000 305,000nd nd <100 <10 <10 <10 P. aeruginosa 350,000 20,000 nd nd <100 <10 <10<10 S. aureus 280,000 495,000 nd nd <100 <10 <10 <10 C. albicans 450,000380,000 nd nd <100 <10 <10 <10 A. niger 450,000 355,000 nd nd 12,550157,500 365,000 365,000 GHB (pH 6.0 + Excipients) 500 mg/cc E. coli500,000 96,000 nd nd <100 <10 <10 <10 P. aeruginosa 350,000 26,000 nd nd<100 <10 <10 <10 S. aureus 280,000 155,000 nd nd <100 <10 <10 <10 C.albicans 450,000 205,000 nd nd <100 <10 <10 <10 A. niger 450,000 131,500nd nd 6,250 1,825 870 370 GHB (pH 6.0 + Excipients) 500 mg/cc E. coli500,000 93,000 nd nd <100 <10 <10 <10 P. aeruginosa 350,000 30,500 nd nd<100 <10 <10 <10 S. aureus 280,000 185,000 nd nd <100 <10 <10 <10 C.albicans 450,000 135,000 nd nd <100 <10 <10 <10 A. niger 450,000 121,500nd nd 5,400 1,785 795 505

[0274] TABLE 21 Result Summary GHB (pH 7.50) Initial Jul. 2, 1998 StartDate 500 mg/cc Conc 0 Day 1 Day 3 Day 7 Day 14 Day 21 Day 28 HCl E. coli97000 82000 19200 nd 1000 <10 <10 <10 P. aeruginosa 48500 29500 520 nd<10 <10 <10 <10 S. aureus 54500 58000 42350 nd 4950 245 <10 <10 C.albicans 58500 38500 1060 nd <100 <10 <10 <10 A. niger 77500 48000 21450nd 46000 46000 38000 54000 Malic Acid E. coli 97000 83000 44450 nd 305070 <10 <10 P. aeruginosa 48500 15650 545 nd <10 <10 <10 <10 S. aureus54500 59500 48400 nd 17400 6500 820 505 C. albicans 58500 44000 6200 nd500 <10 <10 <10 A. niger 77500 35500 24100 nd 28000 49000 44500 44000GHB (pH 7.50) Initial Jul. 2, 1998 Start Date 500 mg/cc Co 0 Day 1 Day 3Day 7 Day 14 Day 21 Day 28 HCl E. coli 9.70E+04 8.20E+04 1.92E+04 nd1.00E+03 <10 <10 <10 P. aeruginosa 4.85E+04 2.95E+04 5.20E+02 nd <10 <10<10 <10 S. aureus 5.45E+04 5.80E+04 4.24E+04 nd 4.95E+03 2.45E+02 <10<10 C. albicans 5.85E+04 3.85E+04 1.06E+03 nd <100 <10 <10 <10 A. niger7.75E+04 4.80E+04 2.15E+04 nd 4.60E+04 4.60E+04 3.80E+04 5.40E+04 MalicAcid E. coli 9.70E+04 8.30E+04 4.45E+04 nd 3.05E+03 7.00E+01 <10 <10 P.aeruginosa 4.85E+04 1.57E+04 5.45E+02 nd <10 <10 <10 <10 S. aureus5.45E+04 5.95E+04 4.84E+04 nd 1.74E+04 6.50E+03 8.20E+02 5.05E+02 C.albicans 5.85E+04 4.40E+04 6.20E+03 nd 5.00E+02 <10 <10 <10 A. niger7.75E+04 3.55E+04 2.41E+04 nd 2.80E+04 4.90E+04 4.45E+04 4.40E+04

[0275] TABLE 22 pH Variable Result Summary Inoculum 0 Day 14 Day 28 GHB,pH 7.5 750 mg/cc Dec. 30, 1997 E. coli 470,000 160,000 <10 <10 P.aeruginosa 437,500 152,000 <10 <10 S. aureus 447,500 330,000 1,935 10 C.albicans 375,000 234,500 <10 <10 A. niger 475,500 395,000 161,500202,000 GHB, pH 7.5 750 mg/cc + 0.2% MP/PP Dec. 30, 1997 E. coli 470,000127,000 <10 <10 P. aeruginosa 437,500 61,000 <10 <10 S. aureus 447,500350,000 <10 <10 C. albicans 375,000 103,500 <10 <10 A. niger 457,500315,000 38,500 6,400 GHB, pH 7.5 750 mg/cc + 0.1% MP/PP E. coli 470,000157,000 <10 <10 P. aeruginosa 437,500 90,000 <10 <10 S. aureus 447,500239,000 <10 <10 C. albicans 375,000 169,000 <10 <10 A. niger 457,500335,000 90,500 99,000 GHB, pH 7.5 xxxxx 750 mg/cc + 0.2% x Potassiumsorbate E. coli P. aeruginosa S. aureus C. albicans A. niger GHB, pH 6.0500 mg/cc + 0.2% Potassium sorbate Dec. 30, 1997 E. coli 470,000 222,000<10 <10 P. aeruginosa 437,500 136,000 <10 <10 S. aureus 447,500 410,000<10 <10 C. albicans 375,000 395,000 <10 <10 A. niger 475,500 405,00049,500 11,150 GHB, pH 6.0 500 mg/cc + Excipients Mar. 12, 1998 E. coli500,000 93,000 <10 <10 P. aeruginosa 350,000 30,500 <10 <10 S. aureus280,000 185,000 <10 <10 C. albicans 450,000 135,000 <10 <10 A. niger450,000 121,500 1,785 505 GHB, pH 9.0 500 mg/cc Mar. 12, 1998 E. coli500,000 320,000 <10 <10 P. aeruginosa 350,000 12,000 <10 <10 S. aureus280,000 530,000 <10 <10 C. albicans 450,000 510,000 <10 <10 A. niger450,000 345,000 158,500 110,500 GHB, pH 9.0 500 mg/cc Mar. 12, 1998 E.coli 500,000 305,000 <10 <10 P. aeruginosa 350,000 20,000 <10 <10 S.aureus 280,000 495,000 <10 <10 C. albicans 450,000 380,000 <10 <10 A.niger 450,000 355,000 157,500 365,000 GHB, pH 6.0 500 mg/cc Dec. 30,1997 E. coli 470,000 221,000 <10 <10 P. aeruginosa 437,500 172,000 <10<10 S. aureus 447,500 320,000 <10 <10 C. albicans 375,000 310,000 <10<10 A. niger 475,500 270,000 48,500 8,600 GHB, pH 6.0 500 mg/cc + 0.2%MP/PP Dec. 30, 1997 E. coli 470,000 163,000 <10 <10 P. aeruginosa437,500 60,000 <10 <10 S. aureus 447,500 243,000 <10 <10 C. albicans375,000 150,500 <10 <10 A. niger 475,500 400,000 <10 <10 GHB, pH 6.0 500mg/cc + 0.1% MP/PP Dec. 30, 1997 E. coli 470,000 206,000 <10 <10 P.aeruginosa 437,500 118,000 <10 <10 S. aureus 447,500 330,000 <10 <10 C.albicans 375,000 221,000 <10 <10 A. niger 475,500 355,000 315 <10 GHB,pH 6.0 500 mg/cc Mar. 12, 1998 E. coli P. aeruginosa S. aureus C.albicans A. niger GHB, pH 6.0 500 mg/cc Mar. 12, 1998 E. coli 500,000199,000 <10 <10 P. aeruginosa 350,000 192,500 <10 <10 S. aureus 280,000300,000 <10 <10 C. albicans 450,000 370,000 <10 <10 A. niger 450,000445,000 22,750 4,050 GHB, pH 6.0 500 mg/cc + Excipients Mar. 12, 1998 E.coli 500,000 96,000 <10 <10 P. aeruginosa 350,000 26,000 <10 <10 S.aureus 280,000 155,000 <10 <10 C. albicans 450,000 205,000 <10 <10 A.niger 450,000 131,500 1,825 370 GHB, pH 7.50 500 mg/cc, HCl Jul. 2, 1998E. coli 97000 82000 <10 <10 P. aeruginosa 48500 29500 <10 <10 S. aureus54500 58000 245 <10 C. albicans 58500 38500 <10 <10 A. niger 77500 4800046000 54,000 GHB, pH 7.5 500 mg/cc, Malic Acid Jul. 2, 1998 E. coli97000 83000 70 <10 P. aeruginosa 48500 15650 <10 <10 S. aureus 5450059500 6500 505 C. albicans 58500 44000 <10 <10 A. niger 77500 3550049000 44,000

[0276] Short term stability testing was carried out as described inAppendix A and results are summarized in—Results of Limited StabilityTesting—Xyrem oral solution—are show as follows: TABLE 23-A ORPHANMEDICAL INC. 13911, Ridgedale Drive Minnetonka, (MN) 55305 DATE: 26 Jan.1999 USA NO.: 333198 CERTIFICATE OF ANALYSIS OXYBATE SODIUM, LIQUIDFORM. (28 DAYS CHALLENGE TEST) LOT: MCH1064-3 PROTOCOL 98126 CODE:ORPHAN MEDICAL REQUISITION: 1741 TEST SPECIFICATION RESULT PROCEDUREDescription Clear to slightly Conforms ORGANOLEPTIC opalescent solution.Potency Report 512 mg/ml (102%) NPLC-793 Impurities total ≦2.0% 0.068%NPLC-793D Impurities specified Gamma-Butyrolactone RRT 1.45: 0.021%NPLC-793D GBL-RRT 1.6 (RRT = 1.6): ≦0.5% RRT 4.17: 0.02% Impurity A (RRT4.3): ≦0.5% Impurities unspecified Ind. imp. ≦0.1% RRT 1.28: 0.02%NPLC-793D RRT 3.79: 0.007% PH Report 7.6 USP <791> Challenge TestConforms to USP Conforms USP 23 <51> S.8 (0, 1, 7, 14, 21, 28 days)

[0277] TABLE 23-B ORPHAN MEDICAL INC. 13911, Ridgedale Drive Minnetonka,(MN) 55305 DATE: 21 Jan. 1999 USA NO.: 331347 CERTIFICATE OF ANALYSISOXYBATE SODIUM, LIQUID FORMULATION LOT: MCH1064-3 PROTOCOL 98126 CODE:ORPHAN MEDICAL REQUISITION: 1741 TEST SPECIFICATION RESULT PROCEDUREDescription Clear to slightly Conforms ORGANOLEPTIC opalescent solution.Potency Report 510 mg/ml (102%) NPLC-793-D Impurities total ≦2.0% 0.36%NPLC-793D Impurities specified Gamma-Butyrolactone RRT 1.46: 0.23%NPLC-793D (RRT = 1.6): ≦0.5% RRT 4.31: 0.1% Impurity A (RRT 4.3): ≦0.5%Impurities unspecified Ind. imp. ≦0.1% *A NPLC-793D PH Report 7.9 USP<791>

[0278] TABLE 23-C ORPHAN MEDICAL INC. 13911, Ridgedale Drive Minnetonka,(MN) 55305 DATE: 26 Jan. 1999 USA NO.: 333197 CERTIFICATE OF ANALYSISOXYBATE SODIUM, LIQUID FORM. (28 DAYS CHALLENGE TEST) LOT: MCH1064-3PROTOCOL 98126 CODE: ORPHAN MEDICAL REQUISITION: 1741 TEST SPECIFICATIONRESULT PROCEDURE Description Clear to slightly Conforms ORGANOLEPTICopalescent solution. Potency Report 258 mg/ml (103%) NPLC-793-DImpurities total ≦2.0% 0.045% NPLC-793D Impurities specifiedGamma-Butyrolactone RRT 1.45: 0.016% NPLC-793D GBL-RRT 1.6 (RRT = 1.6):≦0.5% RRT 4.17: 0.02% Impurity A (RRT 4.3): ≦0.5% Impurities unspecifiedInd. imp. ≦0.1% RRT 3.79: 0.009% NPLC-793D PH Report 7.6 USP <791>Challenge test Conforms to USP Conforms USP 23 <51> S.8 (0, 1, 7, 14,21, 28 days)

[0279] TABLE 23-D ORPHAN MEDICAL INC. 13911, Ridgedale Drive Minnetonka,(MN) 55305 DATE: 21 Jan. 1999 USA NO.: 331346 CERTIFICATE OF ANALYSISOXYBATE SODIUM, LIQUID FORMULATION LOT: MCH1064-3 PROTOCOL 98126 CODE:ORPHAN MEDICAL REQUISITION: 1741 TEST SPECIFICATION RESULT PROCEDUREDescription Clear to slightly Conforms ORGANOLEPTIC opalescent solution.Potency Report 256 mg/ml (102%) NPLC-793-D Impurities total ≦2.0% 0.18%NPLC-793D Impurities specified Gamma-Butyrolactone RRT 1.46: 0.13%NPLC-793D (RRT = 1.6): ≦0.5% RRT 4.31: 0.03% Impurity A (RRT 4.3): ≦0.5%Impurities unspecified Ind. imp. ≦0.1% *A NPLC-793D PH Report 7.9 USP<791>

[0280] TABLE 23-E ORPHAN MEDICAL INC. 13911, Ridgedale Drive Minnetonka,(MN) 55305 DATE: 26 Jan. 1999 USA NO.: 333196 CERTIFICATE OF ANALYSISOXYBATE SODIUM, LIQUID FORM. (28 DAYS CHALLENGE TEST) LOT: MCH1064-3PROTOCOL 98126 CODE: ORPHAN MEDICAL REQUISITION: 1741 TEST SPECIFICATIONRESULT PROCEDURE Description Clear to slightly Conforms ORGANOLEPTICopalescent solution. Potency Report 360 mg/ml (103%) NPLC-793 Impuritiestotal ≦2.0% 0.050% NPLC-793D Impurities specified Gamma-ButyrolactoneRRT 1.45: 0.017% NPLC-793D GBL-RRT 1.6 (RRT = 1.6): ≦0.5% RRT 4.17:0.02% Impurity A (RRT 4.3): ≦0.5% Impurities unspecified Ind. imp. ≦0.1%RRT 1.28: 0.006% NPLC-793D RRT 3.79: 0.007% PH Report 7.7 USP <791>Challenge test Conforms to USP Conforms USP 23 <51> S.8 (0, 1, 7, 14,21, 28 days)

[0281] TABLE 23-F ORPHAN MEDICAL INC. 13911, Ridgedale Drive Minnetonka,(MN) 55305 DATE: 21 Jan. 1999 USA NO.: 331345 CERTIFICATE OF ANALYSISOXYBATE SODIUM, LIQUID FORMULATION LOT: MCH1064-3 PROTOCOL 98126 CODE:ORPHAN MEDICAL REQUISITION: 1741 TEST SPECIFICATION RESULTAT/RESULTPROCEDURE Description Clear to slightly Conforms ORGANOLEPTIC opalescentsolution. Potency Report 363 mg/ml (104%) NPLC-793-D Impurities total≦2.0% 0.21% NPLC-793D Impurities specified Gamma-Butyrolactone RRT 1.46:0.14% NPLC-793D (RRT = 1.6): ≦0.5% RRT 4.31: 0.05% Impurity A (RRT 4.3):≦0.5% Impurities unspecified Ind. imp. ≦0.1% *A NPLC-793D PH Report 8.0USP <791>

[0282] TABLE 23-G ORPHAN MEDICAL INC. 13911, Ridgedale Drive Minnetonka,(MN) 55305 DATE: 26 Jan. 1999 USA NO.: 333195 CERTIFICATE OF ANALYSISOXYBATE SODIUM, LIQUID FORM. (28 DAYS CHALLENGE TEST) LOT: MCH1064-4PROTOCOL 98126 CODE: 1741 ORPHAN MEDICAL REQUISITION: 1741 TESTSPECIFICATION RESULT PROCEDURE Description Clear to slightly ConformsORGANOLEPTIC opalescent solution. Potency Report 461 mg/ml (102%)NPLC-793 Impurities total ≦2.0% 0.065% NPLC-793D Impurities specifiedGamma-Butyrolactone RRT 1.45: 0.018% NPLC-793D GBL-RRT 1.6 (RRT = 1.6):≦0.5% RRT 4.17: 0.02% Impurity A (RRT 4.3): ≦0.5% Impurities unspecifiedInd. imp. ≦0.1% RRT 1.28: 0.02% NPLC-793D RRT 3.79: 0.007% PH Report 7.5USP <791> Challenge test Conforms to USP Conforms USP 23 <51> S.8 (0, 1,7, 14, 21, 28 days)

[0283] TABLE 23-H ORPHAN MEDICAL INC. 13911, Ridgedale Drive Minnetonka,(MN) 55305 DATE: 21 Jan. 1999 USA NO.: 331343 CERTIFICATE OF ANALYSISOXYBATE SODIUM, LIQUID FORMULATION LOT: MCH1064-4 PROTOCOL 98126 CODE:ORPHAN MEDICAL REQUISITION: 1741 TEST SPECIFICATION RESULT PROCEDUREDescription Clear to slightly Conforms ORGANOLEPTIC opalescent solution.Potency Report 454 mg/ml (101%) NPLC-793-D Impurities total ≦2.0% 0.40%NPLC-793D Impurities specified Gamma-Butyrolactone RRT 1.46: 0.26%NPLC-793D (RRT = 1.6): ≦0.5% RRT 4.31: 0.1% Impurity A (RRT 4.3): ≦0.5%Impurities unspecified Ind. imp. ≦0.1% *A NPLC-793D PH Report 7.8 USP<791>

[0284] TABLE 23-I ORPHAN MEDICAL INC. 13911, Ridgedale Drive Minnetonka,(MN) 55305 DATE: 26 Jan. 1999 USA NO.: 333194 CERTIFICATE OF ANALYSISOXYBATE SODIUM, LIQUID FORM. (28 DAYS CHALLENGE TEST) LOT: MCH1064-4PROTOCOL 98126 CODE: ORPHAN MEDICAL REQUISITION: 1741 TEST SPECIFICATIONRESULT PROCEDURE Description Clear to slightly Conforms ORGANOLEPTICopalescent solution. Potency Report 563 mg/ml (102%) NPLC-793 Impuritiestotal ≦2.0% 0.077% NPLC-793D Impurities specified Gamma-ButyrolactoneRRT 1.45: 0.020% NPLC-793D GBL-RRT 1.6 (RRT = 1.6): ≦0.5% RRT 4.17:0.02% Impurity A (RRT 4.3): ≦0.5% Impurities unspecified Ind. imp. ≦0.1%RRT 1.29: 0.03% NPLC-793D RRT 3.79: 0.007% PH Report 7.6 USP <791>Challenge test Conforms to USP Conforms USP 23 <51> S.8 (0, 1, 7, 14,21, 28 days)

[0285] TABLE 23-J ORPHAN MEDICAL INC. 13911, Ridgedale Drive Minnetonka,(MN) 55305 DATE: 21 Jan. 1999 USA NO.: 331341 CERTIFICATE OF ANALYSISOXYBATE SODIUM, LIQUID FORMULATION LOT: MCH1064-4 PROTOCOL 98126 CODE:ORPHAN MEDICAL REQUISITION: 1741 TEST SPECIFICATION RESULT PROCEDUREDescription Clear to slightly Conforms ORGANOLEPTIC opalescent solution.Potency Report 561 mg/ml (102%) NPLC-793-D Impurities total ≦2.0% 0.56%NPLC-793D Impurities specified Gamma-Butyrolactone RRT 1.46: 0.31%NPLC-793D (RRT = 1.6): ≦0.5% RRT 4.31: 0.2% Impurity A (RRT 4.3): ≦0.5%Impurities unspecified Ind. imp. ≦0.1% *A NPLC-793D PH Report 7.9 USP<791>

[0286] TABLE 23-K ORPHAN MEDICAL INC. 13911, Ridgedale Drive Minnetonka,(MN) 55305 DATE: 26 Jan. 1999 USA NO.: 333193 CERTIFICATE OF ANALYSISOXYBATE SODIUM, LIQUID FORM. (28 DAYS CHALLENGE TEST) LOT: MCH1064-4PROTOCOL 98126 CODE: ORPHAN MEDICAL REQUISITION: 1741 TEST SPECIFICATIONRESULT PROCEDURE Description Clear to slightly Conforms ORGANOLEPTICopalescent solution. Potency Report 666 mg/ml (102%) NPLC-793 Impuritiestotal ≦2.0% 0.10% NPLC-793D Impurities specified Gamma-Butyrolactone RRT1.45: 0.025% NPLC-793D GBL-RRT 1.6 (RRT = 1.6): ≦0.5% RRT 4.17: 0.02%Impurity A (RRT 4.3): ≦0.5% Impurities unspecified Ind. imp. ≦0.1% RRT1.28: 0.05% NPLC-793D RRT 3.78: 0.007% PH Report 7.6 USP <791> Challengetest Conforms to USP Conforms USP 23 <51> S.8 (0, 1, 7, 14, 21, 28 days)

[0287] TABLE 23-L ORPHAN MEDICAL INC. 13911, Ridgedale Drive Minnetonka,(MN) 55305 DATE: 21 Jan. 1999 USA NO.: 331336 CERTIFICATE OF ANALYSISOXYBATE SODIUM, LIQUID FORMULATION LOT: MCH1064-4 PROTOCOL 98126 CODE:ORPHAN MEDICAL REQUISITION: 1741 TEST SPECIFICATION RESULT PROCEDUREDescription Clear to slightly Conforms ORGANOLEPTIC opalescent solution.Potency Report 660 mg/ml (102%) NPLC-764 Impurities total ≦2.0% 0.81%NPLC-793D Impurities specified Gamma-Butyrolactone RRT 1.46: 0.43%NPLC-793D (RRT = 1.6): ≦0.5% RRT 4.31: 0.3% Impurity A (RRT 4.3): ≦0.5%Impurities unspecified Ind. imp. ≦0.1% *A NPLC-793D PH Report 7.8 USP<791>

[0288] TABLE 23-M ORPHAN MEDICAL INC. 13911, Ridgedale Drive Minnetonka,(MN) 55305 DATE: 26 Jan. 1999 USA NO.: 333192 CERTIFICATE OF ANALYSISOXYBATE SODIUM, LIQUID FORM. (28 DAYS CHALLENGE TEST) LOT: MCH1064-4PROTOCOL 98126 CODE: ORPHAN MEDICAL REQUISITION: 1741 TEST SPECIFICATIONRESULT PROCEDURE Description Clear to slightly Conforms ORGANOLEPTICopalescent solution. Potency Report 518 mg/ml (104%) NPLC-793 Impuritiestotal ≦2.0% 0.065% NPLC-793D Impurities specified Gamma-ButyrolactoneRRT 1.45: 0.018% NPLC-793D GBL-RRT 1.6 (RRT = 1.6): ≦0.5% RRT 4.17:0.02% Impurity A (RRT 4.3): ≦0.5% Impurities unspecified Ind. imp. ≦0.1%RRT 3.79: 0.007% NPLC-793D RRT 5.99: 0.02% PH Report 7.5 USP <791>Challenge test Conforms to USP Conforms USP 23 <51> S.8 (0, 1, 7, 14,21, 28 days)

[0289] TABLE 23-N ORPHAN MEDICAL INC. 13911, Ridgedale Drive Minnetonka,(MN) 55305 DATE: 21 Jan. 1999 USA NO.: 331335 CERTIFICATE OF ANALYSISOXYBATE SODIUM, LIQUID FORMULATION LOT: MCH1064-4 PROTOCOL 98126 CODE:ORPHAN MEDICAL REQUISITION: 1741 TEST SPECIFICATION RESULT PROCEDUREDescription Clear to slightly Conforms ORGANOLEPTIC opalescent solution.Potency Report 515 mg/ml (103%) NPLC-793-D Impurities total ≦2.0% 0.38%NPLC-793D Impurities specified Gamma-Butyrolactone RRT 1.46: 0.27%NPLC-793D (RRT = 1.6): ≦0.5% RRT 4.31: 0.1% Impurity A (RRT 4.3): ≦0.5%Impurities unspecified Ind. imp. ≦0.1% RRT 3.93: 0.007% NPLC-793D PHReport 7.9 USP <791>

[0290] TABLE 23-O ORPHAN MEDICAL INC. 13911, Ridgedale Drive Minnetonka,(MN) 55305 DATE: 09 Feb. 1999 USA NO.: 330721 CERTIFICATE OF ANALYSISOXYBATE CALCIUM LIQUID FORM. (28 DAYS CHALLENGE TEST) LOT: MCH1064-85PROTOCOL 98126 CODE: ORPHAN MEDICAL REQUISITION: 1741 TEST SPECIFICATIONRESULT PROCEDURE Description Clear to slightly Conforms ORGANOLEPTICopalescent solution. Challenge Test Conforms to USP Conforms USP 23 <51>S.8 (0, 1, 7, 14, 21 and 28 days) Potency Report 501 mg/ml (100%)NPLC-793 Impurities total ≦2.0% 1.2% NPLC-793D Impurities unspecifiedInd. imp. ≦0.1% *A NPLC-793D Impurities specified Gamma-ButyrolactoneRRT 1.46: 0.013% NPLC-793D Report: PH Report 7.3 USP <791> Solubilitystudy Report *B PR 98126 IIA

[0291] TABLE 23-P ORPHAN MEDICAL INC. 13911, Ridgedale Drive Minnetonka,(MN) 55305 DATE: 26 Feb. 1999 USA NO.: 331307 CERTIFICATE OF ANALYSISOXYBATE CALCIUM LIQUID FORM. LOT: MCH1064-85 PROTOCOL 98126 CODE: ORPHANMEDICAL REQUISITION: 1741 TEST SPECIFICATION RESULT PROCEDUREDescription Clear to slightly Conforms ORGANOLEPTIC opalescent solution.Potency Report 508 mg/ml (102%) NPLC-793 Impurities total ≦2.0% 0.70%NPLC-793D Impurities unspecified Ind. imp. ≦0.1% *A NPLC-793D Impuritiesspecified Gamma-Butyrolactone Report: RRT 1.37: 0.054% NPLC-793D PHReport 7.6 USP <791>

[0292] This report summarizes the results of the above described studyand provides a summary of previous development work which evaluatedconditions other than those evaluated in this study. The purposes ofthis information is to define the scope and limitations of theself-preserving properties of Xyrem® oral solution for completion ofpatent application.

[0293] II. Summary of Results:

[0294] A. Preparation of Various Formulations of Sodium Oxybate andFormulations Using an Alternative Salt of GHB.

[0295] 1. Various formulations of sodium oxybate were prepared asdirected in the above Protocol. Sodium oxybate, 500 mg/cc with MalicAcid was not soluble at pH 5.0, and further evaluation of this solutionwas discontinued. All other solutions were successfully prepared asdescribed.

[0296] 2. The preparation of an alternative salt ofgamma-hydroxybutyrate was described as the calcium salt, prepared at 500mg/cc (or maximum possible) with Malic Acid at pH 7.5.

[0297] a. The calcium salt of gamma-hydroxybutyrate was prepared byToronto Research and shipped to NeoPharm for determination of solubilityand evaluation according to the Protocol. The absolute limit ofsolubility, without pH adjustment, was determined to be 700 mg/cc. ThepH of this solution was 8.4. Solutions of lower pH were more difficultto prepare at 500 mg/cc using Malic acid as acidulant. When pH wasadjusted to 6.0 with Malic acid, the solubility of the calcium oxybatewas limited (longer stirring required to solubilize). The desiredsolution of 500 mg/cc, pH 7.5 was prepared with Malic acid as acidulantwithout difficulty. Appearance of the final solution was slightly yellowin color. Copies of the laboratory record for preparation of thesesolutions is available.

[0298] B. Microbial Challenge Testing of the Various FormulationsParepared by MDS NeoPharm.

[0299] The microbial challenge testing was carried as specified in theProtocol and the following table summarizes the results of microbialchallenge testing of various formulations of sodium oxybate and thesingle calcium oxybate formulation prepared. TABLE 24 Testing of Sodiumand Calcium GHB Salts Microbial pH of Solution Challenge Result SodiumOxybate Concentration 1. 500 mg/cc 7.5 (Malic acid) Pass 2. 250 mg/cc7.5 (Malic acid) Pass 3. 350 mg/cc 7.5 (Malic acid) Pass 4. 450 mg/cc7.5 (Malic acid) Pass 5. 550 mg/cc 7.5 (Malic acid) Pass 6. 650 mg/cc7.5 (Malic acid) Pass 7. 500 mg/cc 7.5 (Citric acid) Pass CalciumOxybate Conctration 500 mg/cc 7.5 Pass

[0300] C. Short Term Stability Evaluation of Various Formulations ofSodium Oxybate and a Formulation of Calcium Oxybate.

[0301] Solutions were tested on day zero (preparation day) and day 28according to the described Protocol. The results of the stabilityevaluation are summarized in Table 25 below: TABLE 25 Sodium and CalciumGHB Evaluation Impu- rities Sodium Impu- (Speci- oxybate Potency ritiesImpurities fied - solution mg/cc (%) (Total) (Unspecified) GLB) pH 500mg/cc 512 mg/cc 0.68% 0.041% 0.027% 7.6 pH 7.5 (102%) Malic Acid Day 0Day 28 510 mg/cc 0.36%  0.33% 0.028% 7.9 (103%) 250 mg/cc 258 mg/cc0.045%  0.009% 0.026% 7.6 pH 7.5 (103%) Malic Acid Day 0 Day 28 256mg/cc 0.18% 0.015%  0.16% 7.9 (102%) 350 mg/cc 360 mg/cc 0.050%  0.013%0.037% 7.7 pH 7.5 (103%) Malic Acid Day 0 Day 28 363 mg/cc 0.21% 0.017% 0.19% 8.0 (104%) 450 mg/cc 461 mg/cc 0.065%  0.027% 0.038% 7.5 pH 7.5(102%) Malic Acid Day 0 Day 28 454 mg/cc 0.40% 0.038%  0.36% 7.8 (101%)550 mg/cc 563 mg/cc 0.077%  0.037% 0.040% 7.6 pH 7.5 (102%) Malic AcidDay 0 Day 28 561 mg/cc 0.56% 0.047%  0.51% 7.9 (102%) 650 mg/cc 666mg/cc 0.10% 0.057% 0.045% 7.6 pH 7.5 (102%) Malic Acid Day 0 Day 28 660mg/cc 0.81% 0.077%  0.73% 7.8 (102%) 500 mg/cc 518 mg/cc 0.065%  0.027%0.038% 7.5 pH 7.5 (104%) Citric Acid Day 0 Day 28 515 mg/cc 0.38% 0.007% 0.37% 7.9 (103%) 500 mg/cc 501 mg/cc  1.2%   >0.1% 0.013% 7.3 pH 7.5(100%) (See C of A Malic Acid Attached) Day 0 Day 28 508 mg/cc 0.70%  >0.1% 0.054% 7.6 (102%) (See C of A)

[0302] D. Summary of Pertinent Solubility and Microbial Challenge Dataare Shown in Tables 26 and 27. TABLE 26 Limits of Solubility MaximumSolubility pH of Solution Comments Sodium oxybate  450 mg/cc pH 4 (HCl)25°  500 mg/cc pH 5 (HCl) 25°  600 mg/cc pH 6 (HCl) 25°  750 mg/cc pH6.8 (HCl) 25°  750 mg/cc + pH 10.3 25° 1000 mg/cc pH (unadjusted) 65°Soluble, 25° Gel Calsium oxybate  700 mg/cc pH 8.4 (unadjusted) 25°  500mg/cc pH 6.0 25°

[0303] TABLE 27 Microbial Challenge Results pH of Solution MicrobialChallenge Result Sodium oxybate Concentration (Date) 750 mg/cc (Dec.1997) 7.5 (HCl) pass 500 mg/cc (Dec. 1997) 6.0 (HCl) pass 500 mg/cc +Excipients 6.0 (Malic Acid) pass (Xylitol) (March 1998) 500 mg/cc (March1998) 9.0 (HCl) pass (Borderline aspergillus) 150 mg/cc (BDL 1995) 5.0(HCl) fail (aspergillus only) 150 mg/cc (BDL 1995) 7.0 (HCl) fail(aspergillus and staph) 150 mg/cc (BDL 1995) 3.0 (HCl) fail (aspergillusonly) 150 mg/cc (BDL 1995) 10.3 (unadjusted) fail (aspergillus andstaph) 500 mg/cc (May 1998) 6.0 (Malic Acid) discontinued 500 mg/cc (May1998) 7.5 (Malic Acid) pass 500 mg/cc (May 1998) 9.0 (Malic Acid)discontinued 500 mg/cc (May 1998) 7.5 (HCl) pass 500 mg/cc 7.5 (MalicAcid) pass 250 mg/cc 7.5 (Malic Acid) pass 350 mg/cc 7.5 (Malic Acid)pass 450 mg/cc 7.5 (Malic Acid) pass 550 mg/cc 7.5 (Malic Acid) pass 650mg/cc 7.5 (Malic Acid) pass 500 mg/cc 7.5 (Citric Acid) pass Calciumoxybate Concentration (Date) 500 mg/cc 7.5 (Malic Acid) pass

[0304] All of the compositions and/or methods disclosed and claimedherein can be made and executed without undue experimentation in lightof the present disclosure. While the compositions and methods of thisinvention have been described in terms of preferred embodiments, it willbe apparent to those of skill in the art that variations may be appliedto the compositions and/or methods and in the steps or in the sequenceof steps of the method described herein without departing from theconcept, spirit and scope of the invention. More specifically, it willbe apparent that certain agents which are both chemically andphysiologically related may be substituted for the agents describedherein while the same or similar results would be achieved. All suchsimilar substitutes and modifications apparent to those skilled in theart are deemed to be within the spirit, scope and concept of theinvention as defined by the appended claims.

References

[0305] The following references, to the extent that they provideexemplary procedural or other details supplementary to those set forthherein, are specifically incorporated herein by reference.

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1-64. (Cancelled).
 65. A pharmaceutical composition, consistingessentially of an aqueous solution of about 302.5-750 mg/ml sodiumgamma-hydroxybutyrate, and a pH adjusting agent, wherein the compositionhas a pH of about 6-7.5, and wherein the composition is chemicallystable and resistant to microbial growth, and wherein the composition isfree of preservatives.
 66. The pharmaceutical composition of claim 65wherein the aqueous solution contains about 400-650 mg/ml of sodiumgamma-hydroxybutyrate.
 67. The pharmaceutical composition of claim 65containing a pH-adjusting agent selected from an acid, a base and abuffering agent.
 68. A pharmaceutical composition of claim 67 whereinthe acid is an organic acid.
 69. A pharmaceutical composition of claim68 wherein the organic acid is an alphahydroxy carboxylic acid, inparticular malic acid, citric acid, acetic acid or lactic acid.
 70. Thepharmaceutical composition of claim 67 wherein the acid is an inorganicacid.
 71. A pharmaceutical composition according to claim 70 in whichthe inorganic acid, is hydrochloric acid, phosphoric acid, sulphuricacid, boric acid or nitric acid.